6002729A Model 3340 Laser Aerosol Spectrometer Print

Particle Sizers

Model 3340 Laser Aerosol Spectrometer

Operation and Service Manual

P/N 6002729, Revision A October 2009

Model 3340 Laser Aerosol Spectrometer

Operation and Service Manual

Product Overview 1

Unpacking and System Setup

2

Description of the Model 3340

3

Model 3340 Operation 4

Theory of Operation 5

Maintenance 6

Calibration 7

Troubleshooting 8

Appendixes

ii Model 3340 Laser Aerosol Spectrometer

Manual H is tory

The following is a manual history of the Model 3340 (Part Number

6002729).

Revision Date

Revision A October 2009

iii

Warranty

Part Number 6002729 / Revision A / October 2009

Copyright ©TSI Incorporated / 2009 / All rights reserved.

Address TSI Incorporated / 500 Cardigan Road / Shoreview, MN 55126 / USA

Email Address [email protected]

World Wide Web Site www.tsi.com

Fax No. (651) 490-3824

Limitation of Warranty

and Liability

(effective July 2000)

Seller warrants the goods sold hereunder, under normal use and service as

described in the operator's manual, shall be free from defects in workmanship and

material for (12) months, or the length of time specified in the operator's manual,

from the date of shipment to the customer. This warranty period is inclusive of any

statutory warranty. This limited warranty is subject to the following exclusions:

a. Hot-wire or hot-film sensors used with research anemometers, and certain other

components when indicated in specifications, are warranted for 90 days from

the date of shipment.

b. Parts repaired or replaced as a result of repair services are warranted to be free

from defects in workmanship and material, under normal use, for 90 days from

the date of shipment.

c. Seller does not provide any warranty on finished goods manufactured by others

or on any fuses, batteries or other consumable materials. Only the original

manufacturer's warranty applies.

d. Unless specifically authorized in a separate writing by Seller, Seller makes no

warranty with respect to, and shall have no liability in connection with, goods

which are incorporated into other products or equipment, or which are modified

by any person other than Seller.

The foregoing is IN LIEU OF all other warranties and is subject to the LIMITATIONS

stated herein. NO OTHER EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR

PARTICULAR PURPOSE OR MERCHANTABILITY IS MADE.

TO THE EXTENT PERMITTED BY LAW, THE EXCLUSIVE REMEDY OF THE USER

OR BUYER, AND THE LIMIT OF SELLER'S LIABILITY FOR ANY AND ALL LOSSES,

INJURIES, OR DAMAGES CONCERNING THE GOODS (INCLUDING CLAIMS BASED

ON CONTRACT, NEGLIGENCE, TORT, STRICT LIABILITY OR OTHERWISE) SHALL

BE THE RETURN OF GOODS TO SELLER AND THE REFUND OF THE PURCHASE

PRICE, OR, AT THE OPTION OF SELLER, THE REPAIR OR REPLACEMENT OF THE

GOODS. IN NO EVENT SHALL SELLER BE LIABLE FOR ANY SPECIAL,

CONSEQUENTIAL OR INCIDENTAL DAMAGES. SELLER SHALL NOT BE

RESPONSIBLE FOR INSTALLATION, DISMANTLING OR REINSTALLATION COSTS

OR CHARGES. No Action, regardless of form, may be brought against Seller more

than 12 months after a cause of action has accrued. The goods returned under

warranty to Seller's factory shall be at Buyer's risk of loss, and will be returned, if at

all, at Seller's risk of loss.

Buyer and all users are deemed to have accepted this LIMITATION OF WARRANTY

AND LIABILITY, which contains the complete and exclusive limited warranty of

Seller. This LIMITATION OF WARRANTY AND LIABILITY may not be amended,

modified or its terms waived, except by writing signed by an Officer of Seller.

Service Policy Knowing that inoperative or defective instruments are as detrimental to TSI as they

are to our customers, our service policy is designed to give prompt attention to any

problems. If any malfunction is discovered, please contact your nearest sales office

or representative, or call TSI at 1-800-874-2811 (USA) or (651) 490-2811.

mailto:[email protected]

http://www.tsi.com/

iv Model 3340 Laser Aerosol Spectrometer

Trademarks TSI, TSI logo are registered trademarks of TSI Incorporated.

Microsoft, Windows, are registered trademarks of Microsoft Corporation.

LabVIEW is a registered trademark of National Instrument Corporation.

HyperTerminal is a trademark of Hilgraeve, Inc.

Swagelok is a registered trademark of Swagelok Company of Solon, Ohio, USA.

Celeron is a registered trademark of Intel Corporation.

Q-tips is a registered trademark of Chesebrough-Pond's Inc.

Sensidyne and Gilibrator are trademarks of Sensidyne, Inc.

v

Safety

This section gives instructions to promote safe and proper handling

of the Model 3340.

There are no user serviceable parts inside the instrument. Refer all

repair and maintenance to a qualified technician. All maintenance

and repair information in this manual is included for use by a

qualified technician.

The Model 3340 is a Class I laser-based instrument. During normal

operation, you will not be exposed to laser radiation. However, you

must take certain precautions or you may expose yourself to

hazardous radiation in the form of intense, focused, visible light.

Exposure to this light may cause blindness.

Take these precautions:

Do not remove any parts from the Model 3340 unless you are

specifically told to do so in this manual.

Do not remove the Model 3340 housing or covers while power is

supplied to the instrument.

W A R N I N G

The use of controls, adjustments, or procedures other than those specified in this manual may result in exposure to hazardous optical radiation.

W A R N I N G

High voltage is accessible in several locations within this instrument. Make sure you unplug the power source before removing the cover or performing maintenance procedures.

vi Model 3340 Laser Aerosol Spectrometer

L a b e l s

The Model 3340 has the following labels as shown in Figure 1.

Two Laser Safety Information Labels (front and back frame)

Two Cleaning Port Aperture Labels (Laser Optical Block)

Serial Number Label (back panel)

Calibration Label (Back Panel)

Laser Serial Number Label (Laser Tube)

Danger High Voltage Label (Power Entry Module)

Danger High Voltage Label (Laser Anode Cover)

Danger High Voltage Label (Laser HVPS)

Danger Laser Radiation (Optics Assembly)

Microsoft Windows

® XP

Certificate of authenticity on Drive Bracket

Figure 1 Location of Warning and Information Labels

Safety vii

D e s c r i p t i o n o f C a u t i o n / W a r n i n g S y m b o l s

The following symbols and an appropriate caution/warning

statement are used throughout the manual and on the Model 3340

to draw attention to any steps that require you to take cautionary

measures when working with the Model 3340:

Caution

C a u t i o n

Caution means be careful. It means if you do not follow the procedures prescribed in this manual you may do something that might result in equipment damage, or you might have to take something apart and start over again. It also indicates that important information about the operation and maintenance of this instrument is included.

Warning

W A R N I N G

Warning means that unsafe use of the instrument could result in serious injury to you or cause irrevocable damage to the instrument. Follow the procedures prescribed in this manual to use the instrument safely.

Caution or Warning Symbols

The following symbols may accompany cautions and warnings to

indicate the nature and consequences of hazards:

Warns you that uninsulated voltage within the instrument may have sufficient magnitude to cause electric shock. Therefore, it is dangerous to make any contact with any part inside the instrument.

Warns you that the instrument contains a laser and that important information about its safe operation and maintenance is included. Therefore, you should read the manual carefully to avoid any exposure to hazardous laser radiation.

Warns you that the instrument is susceptible to electro-static discharge (ESD) and ESD protection procedures should be followed to avoid damage.

Indicates the connector is connected to earth ground and cabinet ground.

ix

Contents

Manual History ...................................................................... ii

Warranty .............................................................................. iii

Safety ................................................................................... v

Labels ....................................................................................... vi

Description of Caution/Warning Symbols ................................ vii

Caution ................................................................................. vii

Warning ................................................................................ vii

Caution or Warning Symbols ................................................. vii

About This Manual ............................................................. xiii

Purpose ................................................................................... xiii

Related Product Literature ...................................................... xiii

Getting Help ............................................................................ xiii

Submitting Comments ............................................................ xiv

CHAPTER 1 Product Overview ............................................ 1-1

Product Description ............................................................... 1-1

Applications ........................................................................... 1-2

How the Model 3340 Operates ................................................ 1-2

CHAPTER 2 Unpacking and System Setup ........................... 2-1

Packing List ........................................................................... 2-1

Mounting the Sensor .............................................................. 2-2

Ventilation Requirements .................................................... 2-2

Power Connection .................................................................. 2-2

Connections to the Computer ................................................. 2-2

CHAPTER 3 Description of the Model 3340 ......................... 3-1

Front Panel ............................................................................ 3-1

Inlet .................................................................................... 3-2

Back Panel ............................................................................. 3-2

AC Power Connector ............................................................ 3-3

Pump Exhaust .................................................................... 3-3

Serial Port ........................................................................... 3-3

10/100 Ethernet Port .......................................................... 3-4

Internal Components.............................................................. 3-4

CHAPTER 4 Model 3340 Operation ..................................... 4-1

Quick Start Guide .................................................................. 4-1

Unit Controls ......................................................................... 4-3

Controls Tab ....................................................................... 4-3

Map Tab Primary Controls ................................................... 4-4

Histogram Tab ..................................................................... 4-9

x Model 3340 Laser Aerosol Spectrometer

Configuration Tab ............................................................. 4-14

Calibration Tab ................................................................. 4-14

Collecting Data .................................................................... 4-15

Data File Format ............................................................... 4-16

CHAPTER 5 Theory of Operation ......................................... 5-1

Instrument Subsystems ......................................................... 5-1

Optical System .................................................................... 5-2

Flow System ........................................................................ 5-4

Analog Electronics............................................................... 5-5

Digital Electronics System ................................................... 5-6

On-board PC ....................................................................... 5-8

Particle Coincidence ............................................................. 5-10

CHAPTER 6 Maintenance .................................................... 6-1

Cleaning Optics ..................................................................... 6-1

Laser High Voltage Supply .................................................. 6-1

Laser Safety Information ..................................................... 6-2

Laser Bench Cleaning ......................................................... 6-2

Inlet Jet .............................................................................. 6-5

CHAPTER 7 Calibration ....................................................... 7-1

Calibration Mode Controls ..................................................... 7-2

Configuration Tab ............................................................... 7-2

Map Tab Calibration Controls ............................................. 7-4

Calibration Tab ................................................................... 7-5

Calibration ............................................................................. 7-7

Example: Adding a Calibration Point for 0.269 µm PSL

Particles ........................................................................... 7-7

Set up the Map ................................................................... 7-8

Initial Sampling ................................................................... 7-9

Entering the Calibration Voltage ....................................... 7-10

Gain Stitches .................................................................... 7-13

CHAPTER 8 Troubleshooting ............................................... 8-1

APPENDIX A Model 3340 Specifications .............................. A-1

APPENDIX B Using Serial Data Commands .......................... B-1

Pin Connectors ...................................................................... B-1

Baud Rate .............................................................................. B-2

Format (8-Bits, No Parity) ...................................................... B-2

Stop Bits and Flow Control .................................................... B-2

ASCII Data Output ................................................................. B-2

Data File and Output Format ................................................. B-3

APPENDIX C Computer Related Issues ................................ C-1

Regional Settings and LabVIEW® Software .............................. C-1

Procedure to Allow use of Regional Settings with

Non-Period Local Decimal Points ...................................... C-4

Remote Desktop Operation..................................................... C-8

Contents xi

Bi-directional Serial Command Protocol ............................... C-16

Test Computer Settings (illustrated in HyperTerminal) ....... C-16

Status Command .............................................................. C-17

Start Command ................................................................. C-17

Distribution Command ...................................................... C-18

Map Command .................................................................. C-19

Stop Command ................................................................. C-20

Invalid Commands ............................................................ C-20

Index

Reader’s Comments

F i g u r e s

1 Location of Warning and Information Labels ....................... vi

1-1 Model 3340 Laser Aerosol Spectrometer ........................... 1-1

3-1 Front Panel of the Model 3340 Laser Aerosol

Spectrometer .................................................................... 3-1 3-2 Inlet with Two Guards ...................................................... 3-2 3-3 Back Panel of the Model 3340 Laser Aerosol

Spectrometer .................................................................... 3-2

5-1 Block Diagram of Optical Particle Spectrometer ................ 5-2

5-2 Side View of Optical Block ................................................ 5-3 5-3 Top View of Optical Block ................................................. 5-4 5-4 Schematic Diagram of Flow System .................................. 5-5 5-5 Block Diagram of Analog Electronics ................................ 5-6 5-6 Example Calibration Curve ............................................... 5-9

6-1 Laser Bench Cleaning ....................................................... 6-3

6-2 Laser Bench Optiocs ......................................................... 6-3 6-3 Disconnecting Ferrule Nut ................................................ 6-4 6-4 Inlet Jet ............................................................................ 6-5 6-5 Inserting Tubing into Jet .................................................. 6-6

C-1 Distorted Calibration Curve ............................................. C-3

C-2 Normal Appearance of a Typical Model 3340

Calibration Curve (requires calibration password

to access) ......................................................................... C-3

xii Model 3340 Laser Aerosol Spectrometer

T a b l e s

2-1 Accessories Packing List ................................................... 2-1

8-1 Troubleshooting Symptoms and Recommendations .......... 8-1

A-1 Specifications of Model 3340 ............................................ A-1

xiii

About This Manual

P u r p o s e

This is an operation and service manual for the Model 3340 Laser

Aerosol Spectrometer.

R e l a t e d P r o d u c t L i t e r a t u r e

Model 3076Constant Output Atomizer Manual (part number

1933076 TSI Incorporated)

Model 3079 Portable Atomizer Manual (part number

1930070 TSI Incorporated)

Model 9302 Atomizer Manual (part number 190142 TSI

Incorporated)

Model 9306 Six-jet Atomizer Manual (part number 1930099

TSI Incorporated)

Model 3433 Small Scale Powder Disperser Manual (part

number 1933769 TSI Incorporated)

G e t t i n g H e l p

To obtain assistance with this product or to submit suggestions,

please contact:

TSI Incorporated

500 Cardigan Road

Shoreview, MN 55126 USA

Fax: (651) 490-3824

Telephone: 1-800-874-2811 (USA) or (651) 490-2811

E-mail Address: [email protected]


xiv Model 3340 Laser Aerosol Spectrometer

S u b m i t t i n g C o m m e n t s

TSI values your comments and suggestions on this manual. Please

use the comment sheet, on the last page of this manual, to send us

your opinion on the manual‘s usability, to suggest specific

improvements, or to report any technical errors.

If the comment sheet has already been used, send your comments

to:

TSI Incorporated

500 Cardigan Road

Shoreview, MN 55126

Fax: (651) 490-3824

E-mail Address: [email protected]


1-1

C H A P T E R 1 Product Overv iew

This chapter contains a product description of the Model 3340

Laser Aerosol Spectrometer and a brief description of how the

instrument operates.

P r o d u c t D e s c r i p t i o n

The Model 3340 Laser Aerosol Spectrometer, shown in Figure 1-1,

is a high sensitivity laser particle size spectrometer designed for

sampling and counting airborne particulates from 90 nm to 7.5 µm

using a patented contamination resistant Helium-Neon active cavity

laser. The spectrometer is operated via a built-in computer utilizing

the Windows® XP operating system running an executable

LabVIEW® ―Virtual Instrument (VI)‖ interface to provide instrument

control, data display, recording and output. Each instrument

includes a 10‖ color LCD flat panel display, USB keyboard and

Mouse, 40GB HDD, 3.5‖ FDD and CD-ROM drives. Also provided

are a 10/100 Ethernet interface and 9 pin RS-232 interface.

Figure 1-1 Model 3340 Laser Aerosol Spectrometer

1-2 Model 3340 Laser Aerosol Spectrometer

A p p l i c a t i o n s

The Model 3340 Laser Aerosol Spectrometer has application in the

following areas:

Inhalation toxicology

Atmospheric studies

Ambient air monitoring

Drug-delivery studies

HEPA/ULPA Filter testing and characterization

Indoor air-quality monitoring

Biohazard detection

Basic research

Characterization of test aerosols used in particle-instrument

calibration

Performance evaluations of other aerodynamic devices

H o w t h e M o d e l 3 3 4 0 O p e r a t e s

The Model 3340 operates on the principle that the light scattered by

a particle within an active laser cavity is a direct function of its size.

Particles produce pulses of light during transit through the laser

beam. The light pulses are sensed by a pair of detectors that in turn

are analyzed by four cascading amplifier stages coupled to analog-

to-digital converters for sizing. Particles are aerodynamically

focused to a sample stream diameter smaller than the laser beam

diameter in order to avoid edge effects.

The Model 3340 contains a computer running the Windows® XP

operating system. It is assumed that the instrument user is familiar

with the normal operation of this operating system on a computer.

The operating program LAS-3340_3p3_090519.exe is accessed by a

desktop icon. This program, written in National Instruments

LabVIEW® provides a user-friendly virtual instrument (commonly

called a VI) panel for the control, data display, and data logging for

the Model 3340.

Refer to Chapter 5, ―Theory of Operation,‖ for a detailed description.

2-1

C H A P T E R 2 Unpacking and System Setup

This chapter provides information concerning the accessories

shipped with the sensor and describes basic setup procedures.

P a c k i n g L i s t

Table 2-1 provides a packing list of all items that should have been

shipped to you as the Model 3340 and accessory kit. Please

compare the list to the items you received. If any items are missing,

notify TSI immediately.

Table 2-1

Accessories Packing List

Qty Description

1 Model 3340 Laser Aerosol Spectrometer

1 Model 3340 Laser Aerosol Spectrometer Manual

1 Microsoft Windows® XP Distribution Disk

1 Microsoft®

Office Software License

1 Line Cord

1 USB Mini Keyboard

1 USB Mouse

36 in. Tubing 1/16” × 1/8”

6 in. Tubing 1/8” × 1/4"

1 Zero Count Inlet Filter Assembly

2 Spare Fuses 5 × 20 mm 2A

1 Calibration Certificate

The special dual-box packaging and foam cradle are designed to

protect the Model 3340 from rough handling during shipping. It is

recommended that you retain the shipping box for use when

returning the unit to TSI for service and/or calibration. Take proper

lifting precautions when removing the instrument from the

shipping box.


M o u n t i n g t h e S e n s o r

The Model 3340 Laser Aerosol Spectrometer requires no special

mounting requirements other than the ventilation requirements

(see below). The cabinet has four non-marking rubber feet that give

the instrument a good grip on clean, level surfaces and two

additional feet mounted on retractable legs at the front of the unit

that allow the unit to be angled for user convenience.

Ventilation Requirements

The Model 3340 cabinet is designed to be cooled by room air drawn

in from the bottom of the cabinet and exhausted through the back

of the cabinet.

The cabinet should be installed with at least 2-inch (50-mm)

clearance between the back panel and any other surface. Most

important, the cabinet should be set on a clean, hard surface so

that the exhaust air can move freely from the cabinet.

P o w e r C o n n e c t i o n

Connect the AC power cord (supplied) to the IDC power input

module on the back of the Model 3340 and then into an available

power outlet. It is not necessary to select the correct voltage, the

spectrometer accepts line voltage of 85 to 260 VAC, 50 to 60 Hz,

200 W, single phase. The connection is self regulating.

Toggle the on/off switch at the POWER connection to the on

position to verify the sensor has power.

C o n n e c t i o n s t o t h e C o m p u t e r

There are two USB ports incorporated into the floppy disk/CD-ROM

unit mounted on the front panel. The keyboard and mouse should

be plugged into these ports. Optionally, a USB flash drive may be

temporarily plugged in place of the keyboard for file transfers. There

are 10/100 Ethernet port (RJ45) and RS-232 ports on the I/O

panel above the power inlet module on the back panel. The I/O

panel also contains an exhaust port.

Unpacking and System Setup 2-3

Front Panel USB Ports Back Panel RS-232 and Ethernet

Figure 2-1

Computer Connections to the Model 3340

3-1

C H A P T E R 3 Descr ip t ion of the Model 3340

This chapter describes the front panel, back panel, and internal

components of the Model 3340 Laser Aerosol Spectrometer.

F r o n t P a n e l

The two components of the front panel are the color LCD display

and a combination 3½‖ floppy disk/CD-ROM/USB port unit. The

keyboard and mouse attach via the two USB ports.

The color LCD display is used in combination with the mouse and

keyboard as the main interface to the unit.

Figure 3-1 Front Panel of the Model 3340 Laser Aerosol Spectrometer


The 640 480 pixel LCD display provides continuous real-time

display of sample data, access to the various operating menus

(tabs) and the Windows® XP operating system.

Inlet

The inlet on the top of the unit is protected by two guards to avoid

damage (Figure 3-2). While these guards may look like handles, the

unit should not be picked up by these guards. Typically the unit

ships with the inlet ―zero-count‖ filter attached to one of the guards.

Figure 3-2 Inlet with Two Guards

B a c k P a n e l

As shown in Figure 3-3, the back panel of the Model 3340 allows

for power and data connections. The back panel also has a pump

exhaust port and a fan with fan guard.

Figure 3-3 Back Panel of the Model 3340 Laser Aerosol Spectrometer

Description of the Model 3340 Laser Aerosol Spectrometer 3-3

AC Power Connector

The AC Power Connector accepts the line cord (supplied) to provide

AC power to the spectrometer. The connector has a built-in on/off

switch. Power consumption and line voltage specifications can be

found in Appendix B, Using Serial Data Commands.

Note: Make certain the line cord is plugged into a grounded power

outlet. Position the Model 3340 so the power cord connector is

easily accessible.

Pump Exhaust

Sample aerosol is exhausted through the Exhaust Port.

The pump exhaust connector is a ¼-inch Swagelok®-style

connector that allows control of the exhaust flow. The exhaust can

be vented to a hood or connected in line to equalize pressure when

sampling from a chamber or in an aircraft. The exhaust flow is 10

to 100 sccm. Make certain the exhaust tube allows the exhausted

sample to flow freely (check for crimps and constrictions).

Note: If the aerosol sample is exhausted without tubing, make

certain you do not block the Pump Exhaust.

Serial Port

The Serial Port is a standard RS-232 serial connection that allows

communications between the spectrometer‘s internal computer and

an external computer. In the standard ―virtual instrument‖, when

the ―run‖ button on the histogram tab is toggled, the unit

downloads at the histogram sample rate (user selectable) at

115,200 baud, 8, N, 1. The data format is given in the first two lines

of the data file, subsequent lines are unit data.

Limited external control of the virtual instrument for automated

testing is possible with user-provided software using the RS-232

serial port. See Appendix C, ―Bi-directional Serial Command

Protocol,‖ for details

®Swagelok is a registered trademark of Swagelok Company of Solon, Ohio, USA


10/100 Ethernet Port

The I/O panel includes a standard 10/100 Ethernet (RJ-45)

connection for providing network access to the spectrometer.

I n t e r n a l C o m p o n e n t s

The location of the functional systems and electronics of the

Model 3340 are shown in Figure 3-4 and include:

Digital PC board

Analog PC boards

Flow Strut & Filters

Power PC board

Power Supply

Laser Optical Block

Detector PC board

Figure 3-4

Internal Diagram of the Model 3340 Laser Particle Spectrometer

4-1

C H A P T E R 4 Model 3340 Operat ion

This chapter describes how to set up and operate the Model 3340.

These instructions assume that the Model 3340 is connected to an

AC power source, the power on/off switch on the back panel has

been switched to the ―On‖ position and that the computer has

finished booting. The instrument contains a computer which runs

the Windows® XP operating system. It is assumed that the

instrument user is familiar with the normal operation of this

operating system on a computer. The default user name entered at

the factory is TSIINC and the default password is 3340. Users may

create additional logins to suit their needs.

Q u i c k S t a r t G u i d e

This is an overview of basic operation using the default values set

in the unit when it is shipped. A more detailed explanation of each

control follows the quick start guide.

1. Double-click on the desktop icon for the LabVIEW® virtual

instrument as shown below. (Note: Desktop appearance may

vary from example.)


2. Once the virtual instrument has loaded, click on the Controls

tab (this is typically the default mode) and verify the laser

reference is between 1.0 and 2.8 volts.

3. Click on the Histogram tab. Initially the ―Run‖ button will be

a light gray indicating that the unit is not sampling data. Click

the Run button once to start sampling. The ―Run‖ button will

turn a dark gray indicating the unit is sampling, and clicking

Run again will stop sampling. Click the Stop button to

terminate the program.

With the Zero-Count filter attached to the inlet tubing, the unit

should count fewer than one particle per 5 minutes within 30

minutes of power application. Normally ―Zero-Count‖ operation

is achieved within a few minutes of power application.

Model 3340 Operation 4-3

U n i t C o n t r o l s

The TSI 3340 Laser Aerosol Spectrometer is completely controlled

through the virtual instrument software. All instrument and run

settings can be defined in the software. The following paragraphs

explain in detail which settings are controlled on which tabs of the

software.

Controls Tab

This tab shows the current sample flow rate , the sample flow

rate setting window , the current sheath flow rate , the current

laser reference voltage and the ambient pressure and

temperature.

The sample flow rate may be adjusted in three ways:

Clicking on the top or bottom of the control button adjacent to

the setting window .

Clicking and dragging the slider control .

Entering the desired flow in the control setting window .

The sample flow is controlled by an internal mass-flow controller

that contains integral sensors to adjust for local pressure and

temperature. These sensors are separate from the sensors that are

displayed on the controls tab. Out-of-range settings (greater than

100 sccm or less than ≈0.3 sccm) will cause the flow controller to

shut down.

The sheath flow is factory preset and is not adjustable from the

virtual instrument.


The laser reference voltage is a monitor of the relative laser power

and is not adjustable by the user. Reference values less than 1.0 V

or greater than 2.8 V after warm-up may be an indicator that the

unit needs to be serviced.

The Pressure and Temperature sensors are internal, non-precision

sensors intended for approximate measurements only.

Map Tab Primary Controls

The histogram map values currently in use are displayed in the

map table. As shown here, the map is the default 90 to 7500 nm

(0.09 to 7.5 µm) with logarithmic channel spacing over 99

channels. These settings may be adjusted by an advanced user to

give better resolution over the size range of interest.

The most commonly used map controls are:

Minimum histogram value .

Maximum histogram value

Number of size bins .

Generate a Linear map .

Generate a Logarithmic map .

The ―Commit‖ button will flash yellow any time the map

parameters have been changed. In addition, there are graphical

illustrations of the size scale and number of channels.

Note: The default minimum and maximum sizes may vary from the

actual loaded map.


To change the map, minimum and maximum map values may be

adjusted three ways:

Clicking on the top or bottom of the control button (directly

adjacent to the control setting window).

Clicking and dragging the slider tabs on the size scale bar .

By keyboard entry in the control windows & .

In a similar fashion, the number of size channels may be adjusted

by the button, by clicking and dragging the slider tab on the

channel bar or by keyboard entry in the control window . After

the desired size range and/or channel numbers have been entered,

clicking the Linear button will generate a map with linear

channel spacing between the specified values. Clicking the Log

button will generate a map with logarithmically spaced size

channels. The standard default 90 to 7500 nm size map in the

Model 3340 has logarithmic channel spacing, while the maps used

to generate the instrument calibration reports use linear channel

spacing.

In the following example, the minimum size was set to 90 nm, the

maximum size was set to 189 nm and the ―Linear‖ button was

clicked causing the virtual instrument to generate an evenly spaced

map of 99 size channels between 90 and 189 nm (1 nm bins) and

the Commit button changed to a blinking yellow mode to

indicate changes have been made to the map but they have not

been downloaded into the digital electronics.

Clicking the Commit button causes the new map to be

downloaded from the PC to the digital interface electronics. The

unit will stop sampling when the control is activated. The blue

progress bar adjacent to the control indicates the download status.


While updating the electronics, the progress bar will make multiple

passes before the update is complete. Wait until the bar is stable

before resuming sampling.

Note: The “Commit” button is accessible from all tabs.

The map limits may be set anywhere in the units operating range

(90 to 7500 nm) such as the 90 to 189 nm range in the example

above.

Note: The minimum and maximum settings are integer numbers and

although the size bins are calculated to 2 decimal points it is

generally not useful to set bin widths less than 1nm.

Clear, Load, and Save Controls

Custom maps with variable channel spacing can be created by

entering new values into the map grid. In the example below a

custom map was created to allow the Model 3340 to emulate an old

31 channel instrument formerly used in filter testing.


The map was first cleared using the ―Clear‖ button then the new

map values (in nm) were manually entered and the number of size

channels was changed to 31 (note new position of slider). To save

this map, the ‗Save‖ button was selected and the map was saved

as ―09-3_32ch.map‖ in an appropriate directory. Saved maps may

be loaded by clicking the Load button . It is suggested that

descriptive filenames (such as those shown in the Open dialog box

example below) be used to easily differentiate various maps.

When loading map files ensure that an actual map file is selected

before clicking OK as the virtual instrument does not validate the

selected file. After loading a map file, make sure to set the number

of size bins to the correct value. The number displayed in the size

channel control ( in the figure above) has to match the number of

the last size channel (31 in the figure above). If the value for the

number of size channels is not set correctly, the acquired spectrum

will not be displayed correctly when choosing size as the x-axis.

Note: Saving and Loading maps changes the virtual instrument

default map pointer to the selected map which will be

automatically loaded the next time the virtual instrument

is started.


The map file format is a simple line delineated text file with one size

entry per line as shown below:

Map files can also be created and edited using a text editor such

as Notepad.

Over and Under Controls

The map may be set up to show particle counts outside the range of

the map. In the example below, a map was set up from 100 to

199 nm (1 nm bins) then the ―Under‖ and ―Over‖ controls

were activated. This setup allows for monitoring the activity in the

size range outside of immediate interest.

Note: Having both Over and Under active simultaneously reduces

the total number of channels available to 98 . The 99th

channel size bin was then deleted to make this an “all


oversize particles” channel. When the instrument is sampling,

the first channel will display undersize counts and the last

channel will display oversize counts. These are displayed in

red to differentiate them from the standard histogram counts

as illustrated below. The “Under” and “Over” controls may be

used separately, in combination, or left inactive which is the

standard operating mode.

Calibration Mode Controls

There are additional controls that are normally hidden on this tab

This is discussed in the Configuration Tab section.

Histogram Tab

The Histogram tab will be the most utilized screen in the virtual

instrument as it has the sample controls, histogram data display

controls, and recording control.


Sampling Controls

The ―Run‖ button is displayed in light gray when inactive and

dark gray when active. Clicking on the Run button toggles the unit

sampling process. The sample accumulation time may be set by

direct text entry in the hour/minute/second windows, by clicking

the top or bottom of the button adjacent to the windows or by

clicking and dragging the associated sliders. Sample times may be

set from 0.1 second to 60 hrs, 60 min & 60 seconds. When the unit

is sampling, elapsed time is displayed in the windows to the right of

the time labels . When the ―Forever‖ button is active, the unit

samples continuously. When it is inactive, the unit samples for a

preset number of samples then it stops sampling. The number of

samples is set in the sample window by text entry, slider, or

button. This may be preset from 1 to 99 samples. The current

sample number is displayed in the accumulated sample window .


Histogram Display Controls

The size channels that the histogram displays are set in the map

tab but the histogram controls determine how the data is

presented. The histogram X-axis may be set with the ―Chan Size‖

switch to display by channel number or by bin size and in size

mode the ―Lin Log‖ switch can select either linear or logarithmic

scaling (the X-axis ―Lin Log‖ switch is not visible when set to

channel). The histogram Y-axis may be set with the ―Log Lin‖ switch

for either linear or logarithmic scaling. In addition the Y-axis

may be set to display cumulative channel totals by clicking the

Cumm button . The mode window may be set to ―Counts‖ for

raw counts or ―Conc.‖ for concentration (n/cc) with the button.


The following examples show the same particle data displayed in

many of the available combinations:


Channel Cursor

The histogram has a red X-axis channel cursor that may be

dragged to find the size and total counts for a specific histogram

channel. The Y-axis cursor automatically adjusts to scale the

counts in that channel. Information about the selected channel is

displayed at the bottom of the window.

Record Control

This control is discussed in the Collecting Data section.


Configuration Tab

The configuration tab is not used during typical operation. It

displays the active User Mode , Configuration file name , and

date . There is also a Password Entry window and ―Enter

Password‖ control used to access other user modes. There is also

a switch to normalize histograms to bin width .

The ―Operator‖ mode is the default startup mode and will be used

for majority of the time. The ―Calibration‖ mode is accessible by

entering the calibration password into the password field then

clicking Enter Password. This is discussed in Chapter 7,

Calibration.

Calibration Tab

The Calibration tab is visible but grayed-out as it is not accessible

in Operator mode. This is discussed in Chapter 7, Calibration.


C o l l e c t i n g D a t a

After the Model 3340 is set up and operating with the desired map,

flow, and sample interval, click Run on the histogram tab to start

sampling. Clicking the Record button brings up a dialog box

that allows the user to select a name and location for a data file.

Note: The virtual instrument “pauses” while the record dialog is

being completed. When recording, the “Record” button will be

displayed in dark gray to indicate it is active.

After clicking the Record button, a ―Choose a Data File to Write‖

dialog box will open.

The virtual instrument currently defaults to the root directory (C:\)

for saving data files as illustrated above. As the root directory can

quickly become cluttered with data, it is recommended that the

user create a data directory (such as C:\Data ) or click on My

Documents and save the data there or in a subfolder. The


default filename is based on the date and time the file was

created as: ―yyyymmddhhmmss.xls‖.

The following example illustrates a renamed data file in an

alternate folder (―Data‖ from the previous example). Clicking OK

will start the data recording and return to the Histogram tab—a

feature of the virtual instrument. Data files recorded with an ―xls‖

extension also create a same name ―ini‖ file that records the unit

configuration as illustrated by the pre-existing data file recorded

earlier the same day . If you select an existing file for the

filename, the virtual instrument will append the data to the original

file with a new header to indicate the break in data.

Data File Format

The ―xls‖ data file created by the virtual instrument is a ―text-tab‖

delimited file rather than being a true Microsoft® Excel

® data file. It

can be opened in any text editor; however, it produces a very ―wide‖

file with 114 fields that are more easily viewed in a spreadsheet.

The recording starts with a 2-line header row that defines the data

fields followed by as many rows of data as are recorded by the user.

Note: The virtual instrument was developed to serve the needs of

several different instruments and there are some fields that do

not currently apply to functions in the 3340. This header is too

wide to reproduce here but is shown in a reduced form at the

end of Appendix B.

5-1

C H A P T E R 5 Theory of Operat ion

The Model 3340 is a laser aerosol spectrometer that measures the

size of particles based on the amount of light scattered by the

particle as it passes through an intense laser beam.

In the instrument, particles are confined to the centerline of the

laser beam by sheath air. Side-scattered light is collected by dual

Mangin mirror pairs that focus the collected light onto two solid-

state photodetectors. The electronics convert the light pulses into

electrical pulses the amplitude of which are then measured to

determine the diameter for each individual particle. Transit times

are also measured and minimum and maximum transit thresholds

may be set for each detector gain stage.

The particle range spanned by the Model 3340 is from 0.09 to

7.5 µm and particle data are binned into up to 100 user defined

size channels.

I n s t r u m e n t S u b s y s t e m s

The TSI Model 3340 is an optical-scattering laser-based aerosol

particle spectrometer system for accurately and precisely sizing

particles in the range from 90 nm to 7.5 µm in diameter. It uses

fully user-specified size binning of up to 100 channels anywhere

within its size range.

The spectrometer instrument consists of 5 general subsystems,

described in this chapter.

1. The main optical subsystem responsible for generating the laser

light, detecting the scattering from the particles and providing a

mechanical enclosure for the optical system and for delivery of

the sample aerosol.

2. The flow system for bringing the sample aerosol through the

optical interaction region, including flow control and

measurement.

3. The analog electronics system for amplifying and processing the

particle signals.


4. The digital electronics system for analyzing particle signals,

binning signals according to user-specified bin mappings and

generating a histogram of number of particles in the specified

bins, and for communicating with the PC and system

monitor/control functions.

5. An onboard PC running Windows and a specialized application

GUI for instrument control, setup and data reporting and

collection.

Figure 5-1 Block Diagram of Optical Particle Spectrometer

Optical System

The Optical system consists of

The laser and associated components and optics.

The detection system, including collection optics and

photodetectors and reference monitoring.

Mechanical housing for above.

Laser and Associated Components and Optics

The laser is a Helium-Neon gas laser. It operates in the

fundamental (TEM00) spatial mode on the 633 nm laser line with an

intracavity power ~1 to 10 W. The laser mode has a 1/e2 intensity

diameter of ~400 µm at the interaction region. The standing wave

laser mode is perpendicular to the flow of particles. Particle scatter

is collected in a direction perpendicular to both the particle flow

Theory of Operation 5-3

and the laser standing-wave. As particles traverse the laser mode,

they scatter light into the detection system. The amount of light

scattered is a strong function of the particle size.

Detection System

The detection system consists of two pairs of Mangin collection

optics capable of collecting light over a large solid angle. The

Mangins image the volume of space at which the flow intersects the

laser mode onto a photodiode. There are two pairs of collecting

optics: one pair images onto an Avalanche Photo Diode (APD) for

detecting the smallest particles (the primary scattering detection

system). The other pair (located on the opposite side of the block)

images onto a low-gain PIN photodiode for detection of the upper

size range of the instrument (the secondary scattering detection

system). Each detector is amplified in a current-to-voltage stage

which feeds the analog electronics system. The system can detect

particles as small as 90 nm (≥50% efficiency, <01 count/ 5 minute

dark count rate). The system size sensitivity is limited by several

noise sources: a fundamental noise process from the photon shot

noise on the detected molecular scatter from background gas, a

fundamental noise process from the Johnson noise in the

photodiode transimpedence feedback resistor and from technical

noise of various sources.

Mechanical Housing

The laser and detection optics are built into a sealed mechanical

enclosure (the optical block, Figure 5-2 and Figure 5-3).

Figure 5-2 Side View of Optical Block


Figure 5-3 Top View of Optical Block

Flow System

The mechanical laser mount forms a sealed block around the laser

and the input/output jets. A pump draws on an exhaust jet pulling

flow through the inlet jet and across the laser mode. The input jet

is an aerodynamically focused assembly with a sample nozzle of

500-µm diameter and a sheath nozzle of 760-µm diameter. The tip

of the sheath jet sits close to the edge of the laser mode. Sample

flows are between 5 and 100 sccm and the sheath flow is typically

650 sccm. Particle velocity depends on sheath flow rate, but is on

the order of 50 to 100 m/s. The particles are confined to a region

of space whose extent is limited to a fraction of the laser mode size.

This yields a sizing resolution of approximately 5% of the

particle size.


Figure 5-4 Schematic Diagram of Flow System

Analog Electronics

The analog chain converts the photocurrent of the detector

photodiodes to a voltage and processes that signal (called the

particle signal). The chain is repeated for the primary and

secondary detection systems.

The particle signal is fed into two different AC gain stages, differing

in gain as specified below. In total there are four gain stages: high

and low for each of the primary and secondary detection systems.


Gain Stage Labeling Convention

High Gain Low Gain

Primary detector G3 G2

Secondary detector G1 G0

Gain ratios:

G3/G2 = 50

G2/G1 = 20

G1/G0 = 20

Note: The gain ratios G3:G2 and G1:G0 are pure electrical

amplification gain ratios. The G2:G1 ratio is more complicated

since it involves two independent photodetectors with

independent electronics and on opposite sides of the optical

block. See the discussion in Chapter 7, Calibration.

The gain stages also provide low-pass filtering to the signal. Each

gain stage then feeds its own baseline restoration circuit, which

restores the 0 Volt base line which is disturbed by frequent particle

signals after AC coupling. The particle signal is then passed to a

peak hold circuit which tracks the rise of the photo-signal as a

particle crosses the laser and holds the peak value. The digital

system then processes the signal and when complete, issues a reset

to the baseline restore and peak hold electronics.

Figure 5-5 Block Diagram of Analog Electronics

Digital Electronics System

Digital electronics are used for pulse height analysis and

monitoring and control of on-board systems such as flow meters

and environmental variables.


Analog-to-Digital Converters and Peak Height Analysis

For each of the four gain stages (2 primary, 2 secondary) there is an

associated Analog-to-digital (ADC) converter. The ADCs run a 16-bit

conversion at 100 kHz sample rate. The chain of events is begun as

a particle traverses the laser mode and begins scattering light. The

particle signal from the highest gain stage on the primary detector

(G3) feeds an analog comparator. If the signal exceeds a preset

(user-settable) threshold it generates a particle trigger. The

threshold value is independent of the particular active bin map: it

is should be set to register the smallest detectable particle (90 nm

diameter) under typical operating parameters. After a trigger is

generated and after a small delay to allow the particle signal to

reach its maximum, the 4 ADCs sample the 4 peak-held particle

signals from the four gain stages. Starting from highest gain (G3)

and working down in gain, the first ADC that is not in saturation is

the valid particle ADC. The value of this ADC is read and compared

to a look-up table of bin boundaries previously loaded into memory.

Depending on where in the look-up table the particle signal

belongs, a counter for the appropriate channel is incremented

(There are certain conditions which will post-invalidate a particle

event, for example, if the event falls outside certain timing

requirements.) After the particle signal is sampled, a reset is sent to

the peak hold circuit and the cycle repeats for the next particle.

The look-up table is the heart of the peak-height analysis in this

instrument. It can be reset by the user at any time to generate an

arbitrary bin mapping. The user specifies the boundaries of the

channels and this is automatically converted, via the calibration

curve, relative gains and calibration points into a mapping of

voltages at each of the gain stages. The mapping process is

transparent to the user and occurs every time a bin map is

committed to the instrument (see the Calibration section below).

Monitoring/Control

The digital system also provides monitoring and control of onboard

systems. It reads and sets the mass flow controller for monitoring

and control of the sample flow. It reads the electronic flowmeters for

the sheath flow (flow is controlled by a mechanically-actuated

needle valve). The laser reference from the reference photodiode is

sampled on an ADC and read in the digital electronics module.

Additional housekeeping parameters such as case temperature and

ambient barometric pressure are also monitored. All parameters

which are read by the digital system are logged with the sample

data. All parameters which are set are stored in configuration files.


On-board PC

The on-board PC provides all user interface to the instrument. It is

an 800 mHz Celeron® single-board computer running the Windows

®

XP operating system. The monitor is a standard 640 × 480 LCD

display. All normal OS operations are handled by Windows®, e.g.,

networking, file management, printing, etc. The user interface is a

virtual instrument written in National Instruments LabVIEW® (see

Chapter 4). Communication with the digital electronics system is

via internal RS-232. The update rate of the PC I/O is 10 times per

second.

Calibration

Calibration is an important process for any particle spectrometer

instrument. The Model 3340 with its high resolution and large

number of arbitrarily settable bins poses unique challenges in this

area. Several features have been added to this instrument to make

the calibration process as easy and accurate as possible.

There are 4 separate gain stages which must be ―stitched‖ together

for accurate, seamless sizing across the full dynamic range of the

instrument. The gain stages are labeled in the table in a preceding

section. There are two types of gains that need calibrating:

absolute and relative gains. Relative gains are used to calibrate gain

stages to one another. Absolute gain is used to fix the overall scale

to a known particle size.

The relative gain calibration is somewhat automated, though the

results can always be altered if the user needs to make slight

adjustments. The relative gain calibration works by sampling an

ambient air distribution which contains particles of all sizes

measured by the spectrometer. The instrument detects a particle on

adjacent gain stages (for example G3 and G2), noting the signal size

on both gain stages (in volts). (For example a 150 nm particle might

be 7.5 V on G3 and 0.150 V on G2.) By noting many such events, a

relationship between the signal size of a particle on the two gain

stages can be determined---the relative gain. A linear fit to the data

for many events produces a relative gain and an offset between

adjacent gain stages. By running this procedure on all adjacent

gain stage pairs (G3 and G2; G2 and G1; G1 and G0) a complete

specification of the relative gains can be developed, linking the

optical and electronic signals across the range of the instrument

(which spans 6 decades of signal size in volts).

In addition to the relative gains is the calibration curve, that is, the

shape of the particle signal size (in volts) and the particle size (in

nm). Once the relative gains are known the corrected response for

the entire instrument can be formed from the calibration curve. The

calibration curve has several distinct regions. Since the wavelength

of the instrument is 633 nm, it is expected that all particles below


approximately 300 nm will lie on a sixth-power curve, that is, the

particle signal is a sixth-power of the particle size. Larger particle

sizing is based on an approximation to a Mie curve appropriate for

the scattering response of the instrument. The very largest particles

have a response curve based on the square of the particle diameter.

This is a complicated function which must be both calculated and

confirmed by test particle measurement during factory calibration.

In the event that the user has a preferred curve (empirical or

theoretical, with for example a different index of refraction), the

built-in curve can be overwritten.

Figure 5-6 Example Calibration Curve

In principle, if all the relative gains are known accurately, and the

calibration curve is known, the instrument need only be calibrated

in an absolute sense at one point—any point in fact. In practice it is

best to use a trusted particle or a few trusted particles. For factory

calibration, the particle sizes used are a nominal 0.100 µm

(100 nm) for Gain 3, 0.200 µm (200nm) for Gain 2, 0.500 µm

(500 nm) for Gain 1 and 3 µm for Gain 0. In addition the transition

region in Gain 1 is further defined by nominal 0.9 µm (900 nm) and

1 µm (1000 nm) particles. The specific particles used during

calibration may be verified on the unit calibration certificate.

In some cases, the user may have preferred particles to use for

calibration. In this case as many particles as needed may be used.

If the particles do not all fall on the preset instrument calibration

curve, the calibration curve is altered slightly to ensure that the

calibration particles will return a result which is the stated size of

the particle. The data representing signal size for a given particle

size is entered in the UI and is referred to as calibration points.

Note that alteration of the calibration curve from the preset may be


required in order to accommodate several possible inconsistencies:

for example, particles that have been inconsistently sized with other

methods; nonlinearities in the instrument‘s detection electronics; or

improved empirical data on the non-power law portion of the curve.

One comment on the relative gains is needed. In the particle-size

regions where detection passes from one gain stage to another,

there can be discontinuities in the histograms produced. The

histograms are very sensitive to the relative gain parameters, and

the relative gain parameters are experimental quantities, subject to

statistical and systematic error. The stitching region between G2

and G1 is particularly prominent in this regard, since detection

technique changes between these gain stages (they are physically

different photo-detectors). The relative stitching will never be perfect

and the ability to zoom in on these transition regions can

overemphasize the stitching errors. The user can optimize the

stitching parameters to accommodate unusual requirements in this

area, however, the semi-auto-calibration provided should be

adequate in most cases.

Whenever changes are made to the relative gain parameters, the

calibration curve or the calibration points, the new parameters will

be used in the generation of the next bin map as it is committed to

the instrument.

P a r t i c l e C o i n c i d e n c e

Particle coincidence is typically defined as more than one particle in

the viewing volume of the particle counter creating a signal that

causes the counter to incorrectly classify the particles as a single,

mis-sized particle. Coincidence typically increases somewhat

linearly with particle concentration until the saturation limit is

reached. Above this point instrument operation is unpredictable.

This, along with particle transit time and processing time is

factored into the 3000 particle/second count limit. Coincidence

may be reduced by reducing the instrument flow rate and/or

diluting the sample.

Note: Changing the lower limit of the bin map to exclude small

particles from the histogram does not affect the total number of

particles the instrument has to process and has no effect on

coincidence. This is also why the count limit flag may be

displayed even though relatively few particles are being

counted in the histogram.

6-1

C H A P T E R 6 Maintenance

Most components of the Model 3340 Laser Aerosol Spectrometer are

solid-state and require little or no maintenance. This section

provides information about the maintenance procedures that are

required.

The Model 3340 does not normally require maintenance beyond the

occasional optical cleaning. The optical system is designed to

minimize contamination and it is not unusual for units to operate

for years without any significant contamination. In addition, the

unit is designed with automatic gain control (AGC) which allows

continued accurate particle sizing with varying laser power.

That said, it is possible for contaminants to end up on the laser

optics which can reduce the laser power to a point where the unit

will no longer zero count or provide adequate resolution of particles.

The best indicator of this is to check the laser reference voltage on

the controls tab. If the reference has declined significantly from the

calibration reference recorded on the calibration label then the

optics may be contaminated.

C l e a n i n g O p t i c s

Before starting this operation, read the following safety information

and become familiar with the warning and caution labels found on

the instrument.

Laser High Voltage Supply

The laser in this instrument is powered by a high voltage supply.

There is a warning sticker on this power supply. The supply is

capable of producing peak voltages of 9 KV with an average current

of less than 1 milliamp and continuous voltages of 1.9 KV at a

current of 6 milliamps.


The anode wire from this supply is attached to the laser tube anode

connector. This part of the laser is covered. There is a sticker on the

anode cover denoting the danger here.

WARNING: Failure to observe these high voltage

labels can result in injury or death.

Laser Safety Information

This instrument is a Class 1 laser product as defined by the

National Center for Device and Radiological Health (formerly BRH).

It has an internal cavity with no user-accessible transmitted output

power. The internal cavity develops high resonant energy that is

inaccessible to the user. Warning labels are located near the

cleaning ports.

WARNING: The performance of procedures other

than those specified in this manual may result in

exposure to light radiation that can cause

blindness.

Laser Bench Cleaning

The critical optics of the bench are the laser window and the

external mirror. These optics are accessible via two cleaning ports

illustrated below.

Note: Even though the following cleaning procedures are executed

with the laser turned on, and a cotton swab is inserted into the

laser beam, the procedure is safe. As this procedure is done in

the actual laser cavity, the laser beam is severely attenuated

(or even extinguished) as soon as a solid object is inserted into

the beam.

Maintenance 6-3

Figure 6-1 Laser Bench Cleaning

The following pictures illustrate the optics to be cleaned.

Laser Window HR Mirror

Figure 6-2 Laser Bench Optics

To clean the optics you will need the following tools and supplies:

3/32 inch hex driver for cleaning port screws

PH1 (Phillips #1) screwdriver for lid screws

Cotton swabs (“Q-tips®” or Medical Grade recommended)

Reagent, Spectroscopic or Analytic Grade acetone

The monitor voltage varies during the warm up period. The

instrument should have been on for 30 minutes before performing

this procedure.

®Q-tips is a registered trademark of Chesebrough-Pond's Inc.


Cleaning Procedure

1. Remove the 16 flat Phillips-head cover screws and remove the

unit cover.

2. Attach the zero count filter to the inlet jet tubing.

3. Put the virtual instrument in the controls tab. Monitor the

laser reference display during the optics cleaning procedure.

4. Disconnect the Ferrule nut that connects the input tubing of

the flow assembly to the exhaust jet of the optical bench.

Figure 6-3 Disconnecting Ferrule Nut

5. Remove the 4 cleaning port screws.

6. Remove the cleaning port from the laser window side.

7. Look into the cleaning port and see if there are bright sparkles

on the surface of the window. This indicates contamination

however it is possible to have contamination that does not

show as ―sparkles‖.

8. Wet a cotton swab with a few drops of acetone and shake off

excess. The swab should be slightly wet, not dripping.

9. Immediately swipe across the surface of the window in one

direction.

Note: Use the cotton swab only once. Do not wait an

excessively long time between wetting the swab and

performing the cleaning. The glue of the swab will migrate

to the fibers and contaminate the surface. You may need

to try different cleaning directions to get the surface clean.

An absence of sparkles on the surface and a higher

monitor voltage indicate that the surface is clean.

10. Replace the cleaning port and reconnect the Ferrule nut of the

tubing of the flow assembly. Allow the pump to run for about a

minute and track the monitor voltage.

Maintenance 6-5

11. If the voltage remains higher, disconnect the ferrule nut from

the exhaust jet and clean the external mirror of the optical

bench. Use the previously described procedure. If the optical

bench has not had a significant loss of power, the monitor

voltage should be within 50% of the original voltage.

12. Once the surfaces have been cleaned and the monitor voltage

maximized, do a zero count test to check that there is not a

zero count failure in the first channel of the instrument.

13. If it is not possible to raise the monitor voltage to 50% of the

original level, contact TSI.

14. When finished, re-install the cleaning port screws and replace

the unit cover, securing with the 16 Phillips-head screws.

Inlet Jet

The alignment of the inlet jet is critical to the performance of the

Model 3340. While it is ―locked down‖ it is still possible to move it

under the right circumstances. For this reason, the inlet jet is

completely recessed inside the unit in order to protect it from

bumps, scrapes overtorquing and mishandling.

Figure 6-4 Inlet Jet

The inlet is brought out through the cover port with the supplied

0.063‖ ID/0.125‖ OD tubing. Additional 0.125‖ tubing is supplied

with the instrument along with 0.125‖ ID/0.25‖ OD tubing for

making splices.

In the event that the user needs to change the inlet tubing they will

need to remove the 16 cover screws and the cover in order to access

the Swagelok® fitting on the inlet jet.


The tubing MUST be fully inserted into the jet, approximately 1.3‖

(3.3 cm) from the front of the ferrule as shown below before the

knurled ferrule nut is tightened or a ―particle trap‖ may develop in

the jet.

Note: The knurled ferrule nut should be tightened “Finger tight” only

to avoid potential misalignment of the jet.

Figure 6-5 Inserting Tubing into Jet

In the highly unlikely event that the inlet jet becomes misaligned

TSI recommends factory service. Inlet jet alignment requires the

availability of a monodispersed particle generator, 100 nm

calibration particles and knowledge of their use. Additionally, an

oscilloscope may be required in some cases.

Please contact TSI if you feel that the inlet jet may be misaligned.

7-1

C H A P T E R 7 Ca l ibrat ion

Calibrating the Model 3340 is a moderately complex procedure

requiring some specialized equipment and calibration materials. It

is recommended that the instrument be returned to the factory for

calibration. However, some users may wish to use different particle

standards for the primary calibration points (such as NIST vs. JSR

or Duke) or add additional calibration points beyond what are

normally provided. For those users who wish to perform

calibrations with PSL particle size standards, the following

equipment is required:

Particle Generator capable of supplying filtered air to nebulize

and dry PSL (Polystyrene Latex) calibration particles suspended

in DI water

PSL Calibration Particles (NIST, Duke, JSR, etc.)

Nebulizer(s)

Filtered Deionized water to dilute particle samples

Note: This discusses the basics of using the calibration mode in the

instrument. This does not necessarily produce an ISO

calibration unless ISO standards are followed.


C a l i b r a t i o n M o d e C o n t r o l s

Configuration Tab

The software starts in the operator mode which does not allow

changes to be made in the calibration. To enter the calibration

mode type the calibration password obtained from TSI in the

password window and click the Enter Password button with

the mouse. Contact TSI Customer Service for the calibration

password.

Note that the User Mode window now indicates ―Calibration‖ and

the former ―Enter Password‖ button is now labeled ―Revert

Mode‖. The ―Save‖, ―Load‖ and ―Revert to Factory Configuration‖

buttons are now active.

Calibration 6-3

Save Button

The ―Save‖ button will be used when saving changes to the

configuration. It is highly recommended that this file be renamed

rather than over-writing the original configuration file. A typical

unit is shipped with the configuration file C:\PH\config.cfg as

shown in the ―Active Config‖ window above. TSI‘s suggestion is to

rename the configuration file C:\PH\configmmddyy.cfg where

mmddyy is the month, day, and year the change was made. This

keeps a record of each configuration change and allows for recovery

of a previous configuration in the event an undesired change was

inadvertently saved.

Note: The “Save” dialog box may default to the directory in which

data was last saved. It is recommended that configuration

files always be recorded in the C:\PH directory. The virtual

instrument creates a pointer file called last.cfg which points

to the saved configuration file. The configuration file saves all

major parameters (flow rate, sample time, calibration points,

etc.) used by the virtual instrument. This file is updated any

time a configuration is saved or loaded.

Load Button

The ―Load‖ button is used to open an alternate configuration file.

One use for this is when a specific alternate calibration is desired

for a specific test without altering the normal calibration. An

alternate configuration file can be created and loaded for specific

tests. When the tests are complete, the original configuration can

be loaded which will then be loaded when the virtual instrument

is started.


Revert to Factory Configuration Button

―Revert to Factory Configuration‖ is a way to recover if a

configuration file has become corrupted or was saved with

parameters that cause the unit to function incorrectly. A duplicate

copy of the ―as shipped‖ configuration file named factory.cfg is

loaded when this button is clicked. When using this feature it is

very important that you immediately change the filename from

factory.cfg by clicking on the Save button and entering a new file

name. Otherwise, the original settings in the C:\PH\factory.cfg file

will be overwritten and lost when saving subsequent changes.

Map Tab Calibration Controls

Calibration Mode displays additional controls that are normally

hidden on this tab. The additional controls allow plotting Voltage

or Time histograms for each gain stage (G3-G0 buttons) .

Voltage mode is most useful when calibrating and is discussed in

the calibration example section. Time mode is primarily a

troubleshooting tool and is not discussed in this manual.

Calibration 6-5

Calibration Tab

The calibration tab is available after entering the calibration

password. The Calibration Curve subtab shows the calibration

curve for the unit and the calibration point controls .

Additionally the calibration curve window has a pair of cursors

that can be dragged to indicate size and relative voltage of any

point on the curve. In the example above, the cursors have been set

to indicate the 100 nm calibration point.

The figure above is an enlargement of the calibration control section

from the previous example, illustrating the first calibration point ―0‖

which is set in Gain stage 3 as 870 mV for a 100 nm

particle . A minimum of 1 calibration point (0) is required for unit

operation.


The above screens are illustrations of the saturation points (red)

that separate the gain stages G3 - G0 and the calibration points

(white) that are displayed in the calibration curve. The bottom two

calibration points in the curve are calculated and not changeable

from the virtual instrument.

A minimum of 1 calibration point (point 0 in gain 3) is required for

unit operation. The virtual instrument will extrapolate the

remainder of the curve based on this value. Additional points to

compensate for differences between the theoretical curve and the

actual unit response may be entered (typically at least one point per

gain stage). The standard Model 3340 Laser Aerosol Spectrometer

calibration involves two extra points in the transition section for a

total of six calibration points.

Calibration 6-7

C a l i b r a t i o n

A full calibration procedure is not included here but the steps

involved in creating an intermediate calibration point are illustrated

below. It is assumed that the calibrator has the requisite equipment

and training to generate PSL calibration particles.

Example: Adding a Calibration Point for 0.269 µm

PSL Particles

The unit should be set up and zero-counting with the inlet filter for

at least 30 minutes prior to calibration. Ideally, the reference will be

between 2.2 and 2.7 volts. If the reference is significantly lower

from the voltage recorded on the calibration sticker, the unit may

need cleaning. If the reference is less than 1.0 volt or greater than

2.9 volts, contact TSI for instructions. The flow should be set to

50 sccm, and if desired, the flow can be verified with a reference

standard such as a Sensidyne Gilibrator®, compensating for local

atmospheric pressure and temperature.

®Sensidyne and Gilibrator are trademarks of Sensidyne, Inc.


Set up the Map

The map is typically set to bins ≈1% of the stated particle size with

the map limits set such that the test particle will be near the center

of the map, keeping in mind that the lowest map setting is 90 nm.

Typically all 99 channels are used although this is sometimes

reduced for particles >2 µm. In the case of a 269 nm (0.269 µm)

particle we would use 2.5 nm bins. If we start at 125 nm the

maximum size limit would be 125 + (99 × 2.5) = 372.5 but as we

are limited to integer sizes the upper limit will be set to 373 as

shown here. The map could as easily be set to 130-378 etc.

Calibration 6-9

Initial Sampling

Go to the histogram tab and begin sampling. Particle generation

should result in 500 to 1000 counts in the peak channel in one

minute or more. If the ―Warning! The particle count rate exceeds

the maximum allowed‖ flag is active, the generation rate should be

reduced. As shown here the calculated curve has placed the

primary 269 nm particle peak channel within 1 channel (the

secondary peak is from doublets).

To create an actual calibration point for this particle, the voltage

must be known. Going back to the map tab the ―Voltage‖ and ―G2‖

buttons were selected and a map of 1000 to 8500 mV was created

and committed. Sampling again shows the same particle on a

voltage scale.


We will look for the approximate center of the main peak rather

than the channel with the maximum number of counts. Here, the

center of the peak is ≈5000 mV.

Entering the Calibration Voltage

Selecting the Calibration tab, the Points button is scrolled to

select the next higher calibration point above our calibration

particle. In this case the next higher point was in G1 for the

499 nm particle. Right-clicking within the calibration control area

will bring up a menu and ―Insert Element Before‖ should be

selected. If no higher point had existed, the first blank location

would be used without inserting a new point.

Calibration 6-11

Clicking this will insert a new point with the original number and

will ―bump‖ all higher calibration points up one number. The

resultant calibration curve will be very distorted at this point as the

inserted value is in G0, with 0 mV for 0 nm as shown here. Also,

the ―Commit‖ button will start flashing yellow indicating a

calibration change has been made but not sent to the electronics.

To finish creating the calibration point the gain stage, voltage (as

determined by particle data from the voltage histogram) and

particle size will be entered into the appropriate calibration

windows as shown. When finished, the calibration curve should be

(relatively) smooth and the commit button may be pressed to

download the new curve values.


The particles will then be sampled again with the appropriate size

map to verify that the voltage entered was correct. If the peak is not

in the desired location then the voltage is adjusted until the peak is

in the desired location. In this case, the peak was in the desired

location on the first pass.

If the peak channel was too high, the calibration voltage would be

increased until the peak was in the right channel. If the peak was

too low, the calibration voltage should be reduced. This is a trial-

and-error process.

Once the calibration is deemed correct, the new calibration may be

saved by clicking on the Configuration tab, clicking save and

following the dialog. Changing the filename is recommended as a

precaution.

Note: Clicking stop or removing power from the unit will wipe out

any unsaved changes. This can be useful if changes were

made inadvertently, it is only necessary to stop and restart the

virtual instrument to clear undesirable changes.

Changes in existing calibration points may be made in a similar

fashion by adjusting the calibration voltage without the need to

insert a new calibration point.

Calibration 6-13

Gain Stitches

An additional aspect of calibration are the three Gain ratio ―Stitch‖

tabs (G3:G2, G2:G1 and G1:G0). As the unit has two detectors,

each with two stages of amplification there are four gain stages with

three overlap zones. The stitch function measures ambient particles

that fall in this overlap zone and plots the higher gain vs. the lower

gain for particles that appear in both gain stages simultaneously.

From this, a slope (gain ratio) and offset are calculated that the

virtual instrument uses in order to smoothly ―stitch‖ the data

together at the overlap.

G3:G2 Gain Stitch

Click on the G3:G2 Gain tab. The existing ratio and offset from the

configuration file are used to generate the red line. Click Run to

initiate the stitch data collection. If you want to terminate the stitch

process before it is completed, click Run a second time to stop the

stitch process.

The program will plot each particle that appears simultaneously in

each gain stage. Once enough data have been collected to begin

analysis, the program will create a line corresponding to the center

of the distribution and these numbers will be updated as each

additional particle is measured. The ―Commit‖ button will start

flashing yellow as soon as either the ratio or offset changes from the

previously committed value. The graph will build until the required

number of particles (as indicated in the ―Pts 3‖ box) are reached at

which point the ―Run‖ button will show as inactive (light gray).


At this point, the ―Commit‖ button can be clicked to download the

new stitch to the electronics.

G2:G1 Gain Stitch

As this stitch is measuring two photodetectors across the laser

cavity it is subject to more variation than the previous stitch as

shown here. Fewer particles are collected as ambient aerosol tends

to show a geometric decrease in counts as particle size increases.

Note: The “Align” button is for factory technician use and is not

described here.

Calibration 6-15

G1:G0 Gain Stitch

This stitch requires the fewest number of particles as natural

ambient aerosol typically contains relatively few large particles and

this stitch generally takes much longer to accumulate than the

other stitches. This example taken early in the stitch process shows

about 13 particles have been plotted. The ―Commit‖ button is

flashing and the yellow ―Warning! The particle count rate exceeds

the maximum allowed‖ flag is active. This flag may be ignored

during stitching.

This shows the same stitch run after completion. Note that the ratio

and offset have changed from the earlier example.


When the stitches have been completed, the results may be saved

by clicking the configuration tab and clicking Save as previously

described.

8-1

C H A P T E R 8 Troubleshoot ing

This appendix lists some potential problems and their solutions.

Note: If none of the solutions provided corrects the problem, call your

TSI representative for advice.

Table 8-1

Troubleshooting Symptoms and Recommendations

Symptoms Recommendations

Unit does not turn on. Check for good contact between the power cord and

the wall outlet. Check for power at the outlet. Check

fuses (2A 5 × 20) in power inlet.

Fan comes on but

computer does not boot. Contact TSI for instructions.

LabVIEW® virtual

instrument displays error

messages on startup.

Check for recent changes in the operating system

and software installations. Check if any files have

recently been moved, deleted, etc.

The “Warning! The

particle Count exceeds

the maximum allowed”

flag is active.

This is an indicator that the concentration of aerosol

that the instrument is sampling is too high to

accurately measure. This flag is activated when the

count rate exceeds 3000 particles/sec. Although the

3340 can measure aerosols at concentrations

greater than this value, concentration errors due to

coincidence will increase and some of the particles

will not be counted. To correct this problem the user

may either reduce the flow rate or dilute the sample.

Note: This flag can be ignored when running

stitches (Calibration mode).

“NAN” is displayed in

display windows such as

pressure, temperature,

etc.

“NAN” indicates “Not A Number” which is usually

indicative of a problem with the configuration file.

Check the configuration tab to verify that a valid

configuration file is loaded.

Unit reports low or no

reference voltage.

See “Cleaning Optics” section for cleaning

instructions. If this does not help or if laser is not

ionizing (pink/red glow visible through slot in anode

cover), contact TSI.

No reference or no

particle data above

Gain 2.

Turn the unit off and remove the lid. Check for loose

monitor cable(s) inside unit. NEVER plug/unplug

internal cabling with the power on! Rarely occurs,

but most likely to occur after rough handling of unit.


Symptoms Recommendations

Sample flow rate is

incorrect. Verify the external flow measurement has been

corrected for pressure and temperature.

Compare inlet flow vs. outlet flow. Differences

greater than ≈0.5 sccm may indicate a leak has

developed. Contact TSI if this occurs.

Possible corrupt configuration file. Enter the

calibration password on the Configuration tab. Note

the current configuration file path and name then

click the Revert to Factory Configuration button

and re-measure flow. If this is correct, click save

and rename the configuration file. If the flow is still

incorrect click load and re-load the original

configuration file and contact TSI.

No sample or sheath

flow.

Possible Pump failure or Flow PC board failure.

Contact TSI

A-1

A P P E N D I X A

Model 3340 Speci f icat ions

The following specifications—which are subject to change—list the

most important features of the Laser Particle Spectrometer.

Table A-1

Specifications of Model 3340

Measurement Technique ...................... Light scattering

Particle Type ........................................ Airborne solids and liquids

Particle Size Range .............................. 0.90 to 7.5 µm optical size (PSL equivalent)

Maximum Particle Concentration .......... 3000 particles per second

Display Resolution ................................ Up to 100 user-defined channels

Resolution ............................................ Within 5% at 0.1 m diameter

Sampling Time ..................................... User Selectable from 1 second to 60 hours, 60 min, 60 sec

Flow Rates ........................................... Total flow: 750 ccm, Sheath flow 650 ccm ±25 ccm, Aerosol Sample

10 to 100 sccm ±2.5% @ 50 sccm. Inlet vs. Outlet flow match ±2.5% @ 60ccm

Atmospheric Pressure Correction ......... Sample flow automatically corrected by internal flow controller

Operating Temperature ........................ 10 to 30°C (50 to 86°F)

Operating Humidity ............................... 10 to 90% RH non-condensing

Operating Altitude ................................. Sea level to 4000 meters (13,000 ft)

Laser Source ........................................ >1W intercavity power 633 nm Helium-Neon gas laser

Detectors .............................................. Avalanche Photo Diode (APD) and PIN photodiode

Front Panel Display .............................. 10” Color, 640 by 480 pixels

Power ................................................... 100 to 240 VAC, 50 to 60 Hz, 200 W, single phase

Communications ................................... 10/100 Ethernet (RJ45 Jack), RS232 (9-pin) port (Output only in standard

operating mode)

Outputs ................................................. RS-232 and Ethernet ports

Dimensions (HWD) ............................... 25.4 cm 43.2 cm 55.9 cm (10 in. 17 in. 22 in.)

Weight .................................................. 24 kg (53 lb.).

Fuse ....................................................

Internal fuse not accessible to user

2, 2A 250V 5 20mm in power entry module

3.5A 250V 3AG hard wired in power supply

TSI and TSI logo are registered trademarks of TSI Incorporated.

B-1

A P P E N D I X B Us ing Ser ia l Data Commands

This appendix contains information you need if you are writing your

own software for a computer or data acquisition system.

Information includes:

Pin connectors

Baud rate

Parity

Command definitions and syntax.

P i n C o n n e c t o r s

The Model 3340 has a single 9-pin, D-subminiature connector port

on the back panel labeled SERIAL PORT (See Figure 3-3 and

Figure B-1). This communication port is configured at the factory to

work with RS-232 type devices. Table B-1 provides the signal

connections.

5 4 3 2 1

9 8 7 6

Figure B-1

SERIAL PORT Pin Designations

B-2 Model 3340 Laser Aerosol Spectrometer

Table B-1 Signal Connections for RS-232 Configurations

Pin Number RS-232 Signal

1 — 2 Transmit Output 3 Receive Input 4 — 5 GND 6 — 7 — 8 — 9 —

B a u d R a t e

The baud-rate setting is the rate of communication in terms of bits

per second (baud). The Model 3340 uses a baud rate setting of

115,200. For proper communications, make sure that all software

used with the instrument is set at the appropriate rate.

F o r m a t ( 8 - B i t s , N o P a r i t y )

The Model 3340 RS-232 data output format uses eight data bits

with no parity as the only setting.

S t o p B i t s a n d F l o w C o n t r o l

The Model 3340 uses a Stop bits setting of 1 and a Flow Control

Setting of None.

A S C I I D a t a O u t p u t

The Model 3340 RS-232 output is ASCII text–tab delimited identical

to the saved data format. The 2 line header is sent at the beginning

of the file when the Record button is clicked. The data string is

sent at the end of each sample as defined on the Histogram tab of

the virtual instrument.

Using Serial Data Commands B-3

D a t a F i l e a n d O u t p u t F o r m a t

A typical data file opened in Notepad with extra tabs inserted in the

two header rows to make the columns align correctly (Note: word-

wrap is off). It is generally easier to open data files in a spreadsheet

such as Microsoft® Excel

® software but Notepad illustrates the exact

recorded time format whereas Excel® will often change the time

format.

Field Description

Date Date at the end of the record interval

Time Time at the end of the record interval

Accum Secs. Sample Accumulation Time

Scatter Volts Background Light Level

Current Volts N/A in the Model 3340

Sample sccm Sample Flow Rate (measured)

Ref. Volts Laser Reference Voltage

Temp. Volts N/A in the Model 3340

Sheath sccm Sheath Flow Rate (measured)

Diff. Volts N/A in the Model 3340

Box K Internal Temperature Sensor (°K)

Purge sccm N/A in the Model 3340

Pres. kPa Internal Ambient Pressure Sensor

Aux. Volts N/A in the Model 3340

Flow sscm N/A in the Model 3340

90.00 94.11 Size Range & counts in 1st data channel

9411 98.41 Size Range & counts in 2nd

data channel

98.41 102.91 Size Range & counts in 3rd

data channel

etc.

C-1

A P P E N D I X C Computer Rela ted Issues

R e g i o n a l S e t t i n g s a n d L a b V I E W®

S o f t w a r e

Many European Regional and Language Options use a comma (,) as

a decimal point and may use periods (.) as digit grouping

separators. Our LabVIEW® configuration files are created using a

period (.) as a decimal point. Changing the regional settings in

Microsoft® Windows

® operating system can create a conflict as it no

longer interprets the decimal correctly.

Note: We have not tested to see if decimal points other than (.) and (,)

exist in Windows® operating system but the same issue would

apply to them.

Example: Default Windows® English (United States) Setting vs.

Windows® default French (France) Setting.

Note: Number Format is 123,456,789.00.

C-2 Model 3340 Laser Aerosol Spectrometer

Note: Number format is: 123 456 789,00.

After applying a comma decimal delimiter format and starting

LabVIEW® virtual instrument, note that the Sample flow on the

Controls tab is zero and the Calibration Curve is quite distorted

(calibration password is required to access the curve). Not shown is

the configuration tab which will show a trigger threshold of 0,000

rather than the normal value for the instrument.

Computer-Related Issues C-3

Figure C-1 Distorted Calibration Curve

Figure C-2 Normal Appearance of a Typical Model 3340 Calibration Curve (requires calibration password to access)

This issue has caused confusion and unnecessary instrument

service returns. To avoid this, LabVIEW® software has an

instruction line to ignore the local decimal point. Unfortunately,

this means that the data files produced by the virtual instrument

will continue to use the period delimiter.


Procedure to Allow use of Regional Settings with

Non-Period Local Decimal Points

A method that appears to work (but has not been thoroughly tested)

is to convert the unit‘s configuration and map files to comma

format, leaving LabVIEW® software to use the local decimal point

set in Windows® operating system. This has the advantage that any

data files it writes will also use the local decimal point. To do this,

use Notepad (or Wordpad) to edit the configuration file (typically

config.cfg or config#xx.cfg in the C:\PH directory. If in doubt, look

on the configuration tab in the virtual instrument to verify the

name of the active configuration file it is using. In this example it is

C:\PH\config.cfg.


1. Open this file in Notepad (or Wordpad).

Note: Before editing, save backup copies of any files you are

changing in another directory to preserve the original files!

2. Select Edit>Replace.


3. In the ―Find what‖ field enter a period (.) and in the ―Replace

with‖ field enter a comma (,) (or other local decimal point if

different).


4. Click Replace All then close the Replace dialog box. Note that

the decimal points are now all commas (,).

5. Save the resulting file using the same name and directory as the

original file, i.e., C:\PH\config.cfg.

6. Open the file C:\PH\LAS-3340_3p3_090519.ini. Highlight the

line useLocalDecimalPt=False as shown here and delete it

(alternatively, you could edit this to read

―useLocalDecimalPt=true‖). Save the file and exit.


Now, when the virtual instrument is started, it will open the

converted file with the local decimal points and should read the

values correctly.

Notes: 1) The factory.cfg and map files (map1 and any other user

created maps) should also be converted in a similar

fashion to the local decimal point.

2) This method can also be used to convert the decimal point

to the correct local value in data files written by LabVIEW®

software that ignore the local decimal point as in option 1

above. For large data files we suggest using Wordpad

instead of Notepad as Wordpad performs the conversion

much more efficiently.

3) Notepad and Wordpad are normally found in: Start > All

Programs > Accessories.

R e m o t e D e s k t o p O p e r a t i o n

Note: These instructions assume that Windows® XP Professional is

the operating system on both computers.

The Microsoft® Windows

® Remote Access feature allows remote

control and monitoring of one or more Model 3340 Laser Aerosol

Spectrometers from another PC which may be located on the same

Ethernet network or from an outside network via an Internet

Service Provider.

To use Remote Desktop the 3340 must first be set up to allow

remote connection. Windows® system setup of the instrument‘s PC

to allow Remote Desktop operation is outlined here:

1. Right-click on My Computer and select Properties.


2. Click on the Remote tab and click the Allow users to connect

remotely to this computer box under the ―Remote Desktop‖

section. Make note of the name of the computer and click Apply

then OK.

Ensure that the Model 3340 is connected to an Ethernet network

and that the connection is functioning. The connection

functionality can be tested by trying to access an internet web site

via Microsoft® Internet Explorer

® browser.


If the control PC is not connected to the same physical network, it

must have the necessary permissions to access the network

remotely via the Internet. Contact your network administrator for

assistance if needed as this is beyond the scope of these

instructions.

Accessing the instrument remotely via Remote Destktop:

1. From the control computer, click on Start > All Programs >

Accessories > Remote Desktop Connection.


2. The following dialog should appear:

3. Click on the Options button to expand the dialog box to allow

customization of the connection:


4. On the ―Display‖ tab, set the display resolution to 640×480,

16-bit color to match the normal screen resolution of the

Model 3340.

5. Click More then Drives, in the ―Local Resources‖ tab to allow

access to the control computer‘s drives. This is useful for saving

data as otherwise you can only save data on the remote PC.

►


6. On the ―General‖ tab, enter the full remote computer name in

the appropriate field. For access via the internet contact your

network administrator for instructions. The user name may be

entered here or may be entered when asked to log in to the

remote computer. Click Connect to establish the Remote

Desktop session.

7. You may see a warning screen asking if you trust the

connection. Click Connect to complete the connection.


8. After connecting, you need to log on to the Model 3340

computer. Use the same username and password as when

working on the instrument directly (default: user name: tsiinc,

password: 3340).

9. When working, you should see the desktop of the target

instrument in the Remote Desktop window. Clicking on the

desktop virtual instrument icon should start the virtual

instrument and allow full control.

Note: If you have selected the “Drives” option under “Local

Resources” when setting up the connection, you will have

access to the control computer’s drives for saving the data.

Clicking on the My Computer button in the data file dialog box

will show the 3340’s drives as well as the control computer’s

local and network drives (see screen below).


10. To disconnect from the remote desktop, close the Remote

Desktop window. Click on OK in the popup dialog to

disconnect. The application(s) running on the3340 computer

continues running until they are shut down.

11. For connecting to the instrument on an internal corporate

network from an outside network (such as a home ISP) an

outside remote desktop gateway will be needed on the corporate

network. Setup of this is beyond the scope of this manual.

C: drive on control PC

(PC name is BC003)


B i - d i r e c t i o n a l S e r i a l C o m m a n d P r o t o c o l

The Bi-directional Serial Command protocol is designed to allow

limited remote control operation of the spectrometer via the RS-232

port. It allows the user to start a single sample of a user-defined

length, verify the status of the sample, get the sample distribution

including sample time, flows, reference, etc., stop sampling, and

verify the map that is in use from a separate control computer.

Note: This does not allow remote control of map settings, flow rate,

or configuration/calibration settings. This is primarily useful

for automated test setups where the control computer may also

be controlling flow, temperature, etc., and processing the data.

If this option is selected, a LabVIEW® virtual instrument with this

feature must be installed in place of the standard installed version

which is set for unidirectional output only. A standard M-F RS-232

cable will need to be connected between the test computer and the

spectrometer which is running the virtual instrument. Contact TSI

Customer Service for a copy of the virtual instrument software with

the bi-directional capability.

Test Computer Settings (illustrated in

HyperTerminal®)

Use settings of 115,200 bps, 8 data bits, no parity, 1 stop bit, and

no flow control.

For the illustrations here HyperTerminal® was also set to echo locally,

append linefeeds ,and wrap lines.

®HyperTerminal is a trademark of Hilgraeve, Inc.


Status Command

Format: status <Enter>.

This command verifies the status of the sample. The response of

―Not running‖ indicates the computer and the spectrometer are

communicating and that the program was not currently taking

data. If the program was sampling (whether under RS-232 control

or direct local control), the response would be the total number of

particles counted followed by the seconds remaining in the current

sample.

Note: In all the following examples, the “Enter” key was pressed

after the screenshot was taken as the unit response

overwrites input text line.

Start Command

Format: start n <Enter>.

Where n is the desired sample time in seconds. This command is

used to start a single test sample. In this case a 60 second sample

was started. The response ―OK‖ indicates the command was

accepted.


Entering the previously described status command gives a response

of ―1464, 41.0‖ indicating that the unit had counted 1464 particles

and there were 41.0 seconds left in the sample.

The sample was allowed to finish, then the status command was

repeated. This time the ―Not running‖ response indicates the

sample is finished.

Distribution Command

Format: distribution <Enter>

This command causes the unit to send the sample data to the

control computer in a comma delimited format. In this example

―458‖ is the number of counts in the first channel, ―424‖ is the

number of counts in the second channel, etc. At the end of the

channel data the unit sends the following data: set sample time,

date and time the sample was started, sample flow, sheath flow,

Reference Voltage, Pressure, and Temperature.


Note: If the unit was running, but a sample had not been started, the

distribution data is invalid. If the unit has not finished with the

sample, the distribution data will be an intermediate value in

the sample. There is nothing to indicate that the sample is not

complete, it is recommended to always verify that the status

has returned to “Not running” before requesting the

distribution.

(Distribution data outlined in red)

Map Command

Format: map <Enter>

This command causes the unit to send the bin map currently in

use to be sent to the control computer.

(Map size bins outlined in red)

If the map "Under" option is active, the map is preceded by a -1. If

the map "Over" option is active, the map is followed by 9999

(not shown).


Stop Command

Format: stop <Enter>

This command terminates a sample in progress. In the example, a

60-second sample was started then stopped part way through the

sample. The response ―OK‖ indicates the command was accepted.

Invalid Commands

Any command that is not recognized generates an ―?Invalid

Command!‖ response as demonstrated by entering a misspelled

stop command in the example below.

Index-1

Index

A AC power connector, 3-3

acetone, 6-3 analog chain, 5-5

analog electronics, 5-5

block diagram, 5-6 analog PC board, 3-4

analog-to-digital converter, 5-7

applications, 1-2

Avalanche Photo Diode, 5-3

B back panel, 3-2 baud rate, B-2

bench cleaning, 6-2

bi-directional serial command protocol, C-16 block diagram, 5-2

C calibration, 5-8, 7-1

calibration curve, 5-9

calibration mode control, 4-9

calibration tab, 4-14 caution symbol, vii

channel cursor, 4-13

choose a data file to write, 4-15 Class 1 laser, v

Class 1 laser product, 6-2

cleaning optics, 6-1, 6-3 cleaning port screws, 6-4

cleaning procedure, 6-4

clear control, 4-6

collecting data, 4-15 commit button, 4-4, 4-5

computer connections, 2-2, 2-3

configuration tab, 4-14 connecting computer, 2-2, 2-3

connecting power, 2-2

connectors AC power, 3-3

control, 5-7

controls tab, 4-3

cumm button, 4-11

D data collection, 4-15 data file format, 4-16

default password, 4-1

default user name, 4-1 description, 3-1

detection system, 5-3

detector PC board, 3-4 digital electronics system, 5-6

digital PC board, 3-4

distribution command, C-18

E Ethernet port, 3-4 exhaust port, 3-3

F ferrule, 6-6

ferrule nut, 6-6

disconnecting, 6-4

filters, 3-4 flow strut, 3-4

flow system, 5-4

schematic, 5-5 format, B-2

front panel, 3-1

G gain ratios, 5-6

gain stage labeling convention, 5-6

guards, 3-2

H Helium-Neon gas laser, 5-2 help, xiii

high voltage supply warning, 6-1

high voltage warning, v histogram display controls, 4-11

histogram map, 4-4

histogram tab, 4-2, 4-9 HyperTerminal

®, C-16

I–J inlet, 3-2

inlet jet, 6-5, 6-6

inserting tubing into jet, 6-6

internal components, 3-4 internal diagram, 3-4

invalid command, C-20

K keyboard, USB, 2-1

L LabVIEW desktop icon, 4-1

laser, 5-2 bench cleaning, 6-2

high voltage supply warning, 6-1

Index-2 Model 3340 Laser Aerosol Spectrometer

laser aerosol spectrometer, 1-1

laser optical block, 3-4 laser reference voltage, 4-4

laser safety, 6-2

LCD display, 3-1

load control, 4-6 location of warning labels, vi

M–N maintenance, 6-1

calibration, 7-1

manual history, ii map command, C-19

map controls, 4-4

map limits, 4-6 map tab, 4-4

mechanical housing, 5-3

monitoring, 5-7

mounting sensor, 2-2 mouse, USB, 2-1

O on-board PC, 5-8

operation, 1-2, 4-1

operator mode, 4-14 optical block

side view, 5-3

top view, 5-4 optical system, 5-2

optics, 5-2

cleaning, 6-1, 6-3

cleaning procedure, 6-4 over control, 4-8

overview, 1-1

P packing list, 2-1

particle coincidence, 5-10 particle signal, 5-5

password

default, 4-1 entry window, 4-14

peak height analysis, 5-7

pin connectors, B-1

power connection, 2-2

power PC board, 3-4

power supply, 3-4 pressure sensor, 4-4

product description, 1-1, 3-1 product registration, iii

pulse height analysis, 5-6

pump exhaust, 3-3 purpose of manual, xiii

Q quick start guide, 4-1

R record control, 4-13 related product literature, xiii

relative gain, 5-10

RS-232 signal, B-2

run button, 4-2, 4-10

S safety, v

sample flow, 4-3

sampling controls, 4-10 save control, 4-6

schematic, 5-5

sensor, mounting, 2-2 serial data commands, B-1

baud rate, B-2

format, B-2 pin connectors, B-1

stop bits and flow control, B-2

serial port, 3-3, B-1

designations, B-1 service policy, iii

setting up, 2-1

sheath flow, 4-3 signal connections for RS-232 configurations, B-2

solid-state, 6-1

specifications, A-1 start command, C-17

status command, C-17

stop bits and flow control, B-2

stop button, 4-2 stop command, C-20

submitting comments, xiv

subsystems, 5-1

T temperature sensor, 4-4 test computer settings, C-16

theory of operation, 5-1

trademarks, iv troubleshooting, 8-1

symptoms and recommendations, 8-1

U under control, 4-8

unit controls, 4-3

unpacking, 2-1 USB keyboard, 2-1

USB mouse, 2-1

USB port, 3-1 user mode, 4-14

user name

default, 4-1

V ventilation requirements, 2-2 vi. (see virtual instrument) virtual instrument, 1-1, 4-1

Index Index-3

W–X–Y warning, v

warning labels

location, vi warning symbol, vii

warranty, iii

Windows® XP operating system, 3-2, 4-1

Z zero-count filter, 4-2

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