FHT 59 Si - Home - Stratec services

Thermo Fisher Scientific

Aerosol Monitor FHT 59 Si Technical Specification

Thermo Fisher Scientific Messtechnik GmbH Frauenauracher Straße 96 91056 Erlangen Germany www.thermo.com [email protected] +49 9131 998-0 +49 9131 998-475 fax

© 2010 Thermo Fisher Scientific Inc. All rights reserved. All trademarks are property of Thermo Fisher Scientific Inc. and its subsidiaries unless mentioned otherwise. This document is copyright protected and any reproduction of the whole or any part of this document is strictly prohibited, except with the written authorization of Thermo Fisher Scientific Inc. The contents of this document are subject to change without notice. All technical information in this document is for reference purposes only. System configurations and specifications in this document supersede all previous information received by the purchaser. Thermo Fisher Scientific Inc. makes no representations that this document is complete, accurate or error-free and assumes no responsibility and will not be liable for any errors, omissions, damage or loss that might result from any use of this document, even if the information in the document is followed properly.

Aerosol Monitor FHT 59 Si

Chapter 1

System Overview

The Aerosol Monitor FHT 59 Si is applied for the continuous automatic detection and early warning of aerosol-bound radio nuclides in the air.

A special compensation method eliminates the influence of high concentration levels of natural aerosol-bound radioactivity on the measured values of artificial radioactivity in the air. The use of an Ion-implanted silicon detector allows detecting alpha and beta radiation simultaneously. The artificial beta activity concentration is determined by means of the alpha beta ratio method.

The aerosols suspended in the air are collected on a special filter tape that is transported by a tape feed mechanism. After a pre-defined measurement period of 30 minutes the aerosol deposition spot is transported further by the tenth of the diameter (5 mm).

The Radon/Thoron equilibrium is maintained during a filter step by forwarding the filter tape by only 10 % of the filter diameter spot. A pump primes a constant air flow through the filter tape whereby the aerosol-bound activity is accumulated on the filter. The detector is mounted right above the particulate collection chamber and measures the activity simultaneously during deposition. The results are obtained in units of Bq/m³.

Thermo Fisher Scientific Technical Specification FHT 59 Si 1


The monitor offers the following features: Features Automatic measurement of natural and artificial radioactive alpha

and beta aerosols,

Measuring range for alpha aerosols 0.05 … 0.5 × 106 Bq/m³,

Measuring range for beta aerosols 0.3 … 0.5 × 106 Bq/m³,

Automatic compensation of the natural activity concentration by special evaluation routines,

Monitoring function with fast alarming,

Reliable filter tape feed mechanism,

Omni-directional detector shielding including the particulate collection chamber,

Self-control of the aerosol monitor with signalization concept,

Software for the evaluation of count rates including all relevant statistical criteria,

Evaluation electronics FHT 8000 A,

Air flow 10 … 12 m³/h; low noise maintenance free side channel blower uncontrolled, optional a controllable air flow with a maximum of 8 m³/h is available,

Serial interface for remote data transmission,

Long intervals of maintenance due to large reserve of filter tape,

Compact design in 19"-technique.

2 FHT 59 Si Technical Specification Thermo Fisher Scientific


Chapter 2

Functional Description

Measuring Principle

The analog signals of the aerosol measurement are assigned to the sixteen-fold counter card in the FHT 8000 A via 5 energy thresholds in the detector module input II.

Measured Values The results are obtained in units of Bq/m³ (= time integral of the activity concentration per volume unit).

Limit of Detection

(LD)

The minimum detectable activity concentration is provided according to DIN 25482 (optional ISO 11929):

Artificial α aerosols: 50 mBq/m3 with 30 min sampling time per filter step and 120 min effective reference time and an air flow of more than 10 m³/h.

Artificial β aerosols: 300 mBq/m3 with 30 min sampling time per filter step and 120 min effective reference time and an air flow of more than 10 m³/h.

With a statistical probability of 5 % for an error of the first kind (false alarm). With a statistical probability of 5 % for an error of the second kind (contamination not detected) is higher by the factor of 2.



Chapter 3

Hardware Key Components

System Components

The Aerosol Monitor FHT 59 Si mainly consists of the following system components:

particulate collection module with integrated micro controller,

ion-implanted Si-detector with lead shielding,

pumping unit with air flow measurement,

measuring channel FHT 8000 A,

19"-rack housing for all components.

Pump Side channel blower,

Oil-free,

Air-cooled.

Detector Ion-implanted Si-detector with a diameter of 50 mm for the simultaneous detection of alpha and beta activity with integrated pre-amplifier.

The efficiency values of this detector related to 4π geometry (measured under operation conditions, source with a diameter of 50 mm in the particulate collection chamber) account to:

Radio nuclide ε [%] 60Co 6 ± 1 90Sr / 90Y 20 ± 3 137Cs 19 ± 2 204Tl 18 ± 2 241Am 15 ± 2



Shielding Omni directional lead shielding made of ring elements above the filter drawer with top lid.

Ring elements, lead 50 mm, with top lid; shields detector plus pre-amplifier.

Measuring Channel

FHT 8000 A

The measurement channel FHT 8000 A is used as evaluation unit. The measurement channel contains all additionally required assemblies for supplying the detector and calculating the measurement values. A keyboard with a trackball is available in an additional 19" drawer. It is possible to connect an external TFT monitor.

16 × digital IN

14 × digital OUT

4 × USB

1 × Firewire IEEE 1394

3 × serial port RS 232

1 × Parallel port

1 × Ethernet

All evaluation routines are stored in the FHT 8000 A as software modules and include monitoring routines for the operation state. To avoid data loss in case of short term power failures, the FHT 8000 A is equipped with a back-up battery. The operating modes can be transmitted to a remote observation station via the system interfaces. All measurement values and the system status can also be transmitted.



Chapter 4

Software

The FHT 8000 A includes all functions and programs relevant for the operation of the monitor. Hereby the full functionality of the monitor is established in stand-alone as well as in network operation.

Program modules for the following functions are available:

Start-up routines (setting parameters)

Data acquisition and evaluation routines

Air flow measurement

Limit value control

Calibration and Recurrent Calibration Check

Measurement of background signal

Control of tape feed mechanism

After powering on the monitor starts automatically. The main menu appears displaying the current measured values of the activity concentration.



By pressing buttons the sub-menus Data and Errors can be accessed. The data menu displays all input parameters relevant for the data analysis. For example the filter activity, pressure, temperature and air flow are displayed in physical units.

In case of an error the corresponding text messages of the underlying physical reasons are displayed in the error menu.



By pressing the button History, 150 data sets of the most important values are shown in line diagrams.

Via the recurrent calibration check (RCC) menu background count rates and the calibration factor can be determined by manually inserting the reference source into the particulate sampling unit.



Chapter 5

Technical Data

Parameter Min. Typ. Max. Unit Condition/Note

Measuring Range α

0.05 0.5 × 106

Bq / m³

Measuring Range β

0.3 0.5 × 106

Bq / m³

LD for α (acc. to DIN 25482)

0.05 Bq / m³

LD for β (acc. to DIN 25482)

0.3 Bq / m³

Cycle meas. duration = 30 min,

Full meas. duration = 120 min,

Air flow > 10 m³/h

amb. DR level approx. 100nSv/h

Efficiency 6 ± 1

20 ± 3

19 ± 2

18 ± 2

15 ± 2

% 60Co 90Sr/90Y 137Cs 204Tl 241Am

Cross-sensitivity 5 µSv / h Related to 137Cs

Radiological



Parameter Min. Typ. Max. Unit Condition / Note

Ambient Temperature

• operating

• storage

+15

+15

+30

+30

°C

on request other ranges of ambient temperature are available

Permitted Temp. Gradient

15 K/h

Sampled Air Intake Temperature

-5 +45 °C

Barometric pressure

• operating

• storage

900

900

1050

1050

hPa

on request other ranges of barometric pressure are available

Rel. Humidity of Sampled Air at Intake

20 80 % R.H.

Rel. Humidity

• storage

20 80 % R.H.

non-condensing

on request other ranges of relative humidity are available

Environmental Conditions


Mains Voltage 230 V AC, single phase

Mains Frequency

50 Hz Optional: 60 Hz

Power consumption

2.4 kVA

Electrical Connection


Height 1600

2000

mm Standard version

System version

without packing

Width 600 mm without packing

Depth 800 mm without packing

Weight 230 kg net, without packing

Cabinet 19 inch

Cabinet height 32

41

U Stand alone version

Systems version

Dimensions and Weight




Diameter 50 mm

Cross-sensitivity

5 µSv / h for 137Cs

Operating Voltage

70 V

Shielding 50 mm lead, all directions

Detector


Degree of precipitation

99.97 % Test aerosols with particulate diameter < 1 µm

Degree of precipitation

99.95 % Radioactively induced test aerosols with particulate diameter < 0.3 µm

Filter length 42 m

Filter width 60 mm

Filter grade S According to DIN 24184

Aerosol Filter


Air Flow 8

10

12

m3 / h Type: 2BH1

Type: SE 3

Supply Voltage

230 V AC

Supply Frequency

50

50/60

Hz Type: SE 3

Type: 2BH1

Power Consumption

2.1 kW

Pump



Electronics FHT 8000 A

Key features

• 16 × digital IN

• 14 × digital OUT

• 4 × USB

• 1 × Firewire IEEE 1394

• 3 × serial port RS 232

• 1 × Parallel port

• 1 × Ethernet

Key features

Filter tape feed mechanism with autonomous micro controller

Collecting cross sectional area 2000 mm²

Particulate Collection Module



Chapter 6

Options

Analog Outputs

2 ea 0/4 - 20 mA analog outputs with driver software for:

• ratemeter artificial α activity concentration

• ratemeter artificial β activity concentration

Linear of logarithmic scale selectable.

Option 1

Option 2 Emission Rates

0 - 10 V analog input for external stack volume flow gauge.

Software module for the calculation of emission rates from the activity concentration values (Bq/m³) and the stack volume flow /m³/h). The emission rates are calculated in units of Bq/h and Bq/day.

Option 3 Data Transfer

The monitor is equipped with a RS232/V24 interface. The set of commands for data transmission is compatible to NetView.

Customer-specific transmission protocols can be implemented on request.

Option 4 Potential-free Digital Outputs

Relays with changeover contacts for a load up to 250 V/6 A

• Failure

• Alarm 1 α artificial concentration

• Alarm 1 β artificial concentration

• Alarm 1 α natural concentration

• Alarm 2 α artificial concentration

• Alarm 2 β artificial concentration

• Alarm 2 α natural concentration




Chapter 7

Consumables

Item Reference number

Fiber Glass Filter Tape (1 ea) KT149248089

Chapter 8

Reference Sources

Reference Source 241Am

Ref. no. SM149470026

Source activity: 3 kBq

Reference Source 90Sr

Ref. No. SM149475033

Source activity: 3.3 kBq

Chapter 9

Documentation Included

1 ea. Combined Hardware-Software Manual

1 ea. USB-Stick with Program, Configuration Utility and System Backup

Documents

FHT 59 Si - Home - Stratec services