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Characterization &Optimization

ofTemperature Sensor Using

LABVIEW

Completed By :

Shabnam Niknezhad

Samreen Shaikh

Guide :

Prof. SAJID NAEEMMSc Electronic Science

Department of Electronic Science

Poona College of Arts , Science & Commerce


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AIM & OBJECTIVESAim:

To study of LabVIEW and its application.

Objectives:

Characterization and Optimization of temperature sensors.

To interface DAQ card with LabVIEW. To design ON/OFF controller to control Heater.

To develop basic programming architectures.

To develop Lab VIEW software for data acquisition, display

and/or control purpose. To create application that use plug in DAQ device

To develop necessary interface hard ware so as to accumulate

variety of test and measurement procedure.

To study different transducers under the control of virtual lab.


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INTRODUCTION The primary objective of process control is to control physical

parameter such as temperature, pressure, flow rate, level, force, lightintensity and so on. As these parameter can change either

spontaneously or because of external influences, we must constantly

provide corrective action to keep these parameters constant or within

the specified range.

To control process parameter, we must know the value of that

parameter and hence it is necessary to measure that parameter.


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An instrumentation system consists of three majorelements :

1. input device2. signal conditioning circuit

3. output device.

The input quantity for most instrumentation system

is non electrical in order to use electrical methods and

techniques for measurement the non electrical quantity is

converted into proportional electrical signal by a device

called transducer.


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Transducer A transduceris a device that converts one form of energy to another.

Energy types include electrical,mechanical,

electromagnetic (including light), chemical, acoustic

or thermalenergy.

While the term transducercommonly implies the use of a sensor/detector,

any device which converts energy can be considered a transducer.

Transducers are widely used in measuring instruments.

Bioelectrical TechnologyAt the heart of this system a wireless

microelectromechanical system (MEMS)

sensor in the contact lens that acts as

a transducer, antenna, and mechanical

support for read-out electronics.


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Temperature sensor - overview In many systems, temperature control is fundamental.

There are a number of passive and active temperaturesensors that can be used to measure system

temperature, including:

1. thermocouple,

2. resistive temperature detector,3. thermistor,

4. silicon temperature sensors.

These sensors provide temperature feedback to the

system controller to make decisions such as, over-

temperature shutdown, turn-on/off cooling fan,

temperature compensation or general purpose

temperature monitor.


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Block Diagram

Signals are input to a sensor, conditioned, converted

into bits that a computer can read, and analyzed to

extract meaningful information.


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Study of LabVIEW


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(Laboratory Virtual Instrument EngineeringWorkbench.)

Lab VIEW is a graphical programming

language that uses icons instead of lines oftext to create programs.

Lab VIEWis a platform and development

environment for a visual programminglanguage from National Instruments.


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virtual instruments

Lab VIEWprograms are called virtualinstruments, or VIs, because their

appearance and operation imitate physical

instruments, such as oscilloscopes andmultimeters.

After build the user interface, add code using

VIs and structures to control the front panelobjects. The block diagram contains this

code.


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LABVIEW INTRODUCTION

Two sets for development Front Panel

Block Diagram

Wiring connections

LabVIEW Conventions

Running LabVIEW programs


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LABVIEW Front Panel

It is the user interface for the VI.

Used to display Controls or Indicators.

It contains the Controls palette.

Highly customizable.


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LABVIEW Block Diagram

Actual program.

Invisible to user.

Read left to right, like a book.

The block diagram provides the area for the graphical code

The

Functions

Palette


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LabVIEW Palettes

1- The Front panel contains:

The Controls Palette

2- The Block Diagram panel contains:

The Functions Palette


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The Controlspalette contains the controls and

indicators that used to create the front panel.

ControlsIndicators


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Some Controls & Indicators


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2- Functions Palette

To open the Functions palette from the blockdiagram window :

Or click the mouse right button.


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Some Functions


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Terminals:

When you place a control(or indicator) on the

FRONT PANEL

LabVIEW automatically

creates a corresponding

control(or indicator)

terminalon the

BLOCK DIAGRAM

B i i d i bl k di


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Basic wires used in block diagrams

and corresponding types:

Each wire has different styleor color, depending on

the data type that flows through the wire:


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LabVIEW Conventions

Front panel itemsControls and indicators

Block diagram items

Program structures (loops, case structures, math, etc.)

Controls vs. Indicators

Wires attach to controls on the right (give values)

Wires attach to indicators on the left (receive values)

Wiring colors

Wires are color coded to correspond to data types


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Controls and Functions Palettes

Graphical, floating palettesused to place controls andindicators on the front panel,or to build the block diagram.

Controls Palette

(Front Panel)

Functions Palette

(Block Diagram)


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Creating afront panel

Right click to selectthe controls palette

Drag and dropthe components

As you placecomponents acorrespondingterminal will appearin the diagramwindow


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Wiring the diagram

Right click toselect thefunctions palette

Drag and dropfunctions

Select the wiring tool

Drag the wirebetween terminals


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Basic Examples :

LabVIEW is written on graphical structure.

While in LabVIEW summationis a function and it is represent

by following symbol.

In LabVIEW, such mathematical and logical functions are

represented graphically.


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Addand multiplytwo given numbers anddisplay the results


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Converting C to F

F = (1.8 * C) + 32

Control

Indicator


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Introduction of DAQ card


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What is DAQ System

DAQ systems capture, measure, and analyze physicalphenomena from the real world.

Light, temperature and pressure are examples of the

different types of signals that a DAQ system can measure.

Data acquisition is the process of collecting and measuringelectrical signals and sending them to a computer forprocessing.

Electrical signals comes from Transducers.

The building blocks of a DAQ system includes:


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The building blocks of a DAQ system includes:

1. Transducer: A device that converts a physicalphenomenon such as light, temperature, pressure, orsound into a measurable electrical signal such as voltageor current.

2. Signal: The output of the transducer.3. Signal conditioning: Hardware that you can connect to the

DAQ device to make the signal suitable for measurementor to improve accuracy or reduce noise.

4. DAQ hardware: Hardware you use to acquire, measure,and analyze data.

5. Software: NI application software is designed to help youeasily design and program your measurement and controlapplication (LABVIEW).


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Why Signal Conditioning

To measure signals from transducers, you must convert them

into a form a measurement device can accept. Common types of signal conditioning include amplification,

linearization, transducer excitation, and isolation.


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What type of device to use

The trade-off usually falls between :

1- Resolution (bits) & Code Width

2- Sampling rate (samples/second)

3- Number of channels, and data transfer rate(usually limited by bus type: USB, PCI, PXI, etc.).


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Types of Data Acquisition and Control

Devices


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DAQ Device Properties

DAQ devices have four standard

elements:

1. Analog input (AI)

2. Analog output (AO)

3. Digital I/O (DIO)4. Counter/Timers


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USB DAQ : USB -6008 & USB -6009 LowCost USB DAQ.

The National Instruments USB-6009 provides basic data

acqusition

functionality for applications such as simple data logging,

portable measurements , and academic lab experiments.

The NI USB _6008 and NI USB 6009 are ideal for students.

Create measurement application

by programing the NI USB-6009

using LabVIEW and NI_DAQmx

driver software for Windows.


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Feature of DAQ 6009

Eight 14-bit analog inputs.

12 digital I/O lines.

2 analog outputs.

1 counter.

Analog Digital

1

32

17

16


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DAQ6009 Details

Overlay Label with Pin Orientation Guide

Comb icon Jack

Screw Terminal Blocks

Signal Labels


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NI USB-6009 Pins

How to Select DAQ Device &


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How to Select DAQ Device &

Accessories

Open the Labview program, in the Block Diagram

select functions, express input then select the

DAQ Assistanticon.


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(Input & Output Channels)

Select Analog Input so as to input your

analog data to the computer and Labview.

How to Select DAQ Device


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How to Select DAQ Device(Input & Output Channels)

We have 16 physical input channels from ai0

to ai15, select a channel like ai0.


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ow o e ec ev ce


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ow o e ec ev ce(Input & Output Channels)

Now make the connections and select test

then Run to see the input voltage.

How to Select DAQ Device


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How to Select DAQ Device(Input & Output Channels)

Example


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Introduction of Sensors

LM35


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LM35

The LM35 is an integrated circuit sensor

that can be used to measure

temperature with an electrical output

proportional to the temperature (in oC).

What Can Expect When


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What Can Expect When

Use An LM35? The output voltage is converted to temperature by a simple

conversion factor. The sensor has a sensitivity of 10mV / oC.

Use a conversion factor that is the reciprocal, that is 100 oC/V.

The general equation used to convert output voltage to

temperature is:

Temperature ( oC) = Vout * (100 oC/V)

So if Vout is 1V , then, Temperature = 100

o

C

The output voltage varies linearly with temperature.

Why Use LM35s To Measure


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Why Use LM35s To Measure

Temperature?

Measure temperature more accurately than a

using a thermistor.

The sensor circuitry is sealed and not subject

to oxidation, etc.

The LM35 generates a higher output voltage

thanthermocouples and may not require that

the output voltage be amplified.


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How does LM35 work?

It has an output voltage that is proportional

to the Celsius temperature.

The scale factor is 10mV/oC .

The LM35 does not require any external

calibration or trimming and maintains an

accuracy of +/-0.4 oC at room temperature

and +/- 0.8o

C over a range of 0o

C to +100o

C. Vc= 4 to 30v

5v or 12 v are typical values used.

Photo of the LM 35 wired on a


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Photo of the LM 35 wired on a

circuit board.

The white wire in the photo goes to thepower supply.

Both the resistor and the black wire go to

ground. The output voltage is measured from the

middle pin into ground .

Power supply

Output voltage Ground

R l Pi t


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Real Picture

LM35

Result in Block Diagram


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Result in Block Diagram

Temperature ( oC)= Vout * (100 oC/V)

Convertfrom

Dynamic Data

R lt i F t P l (h ti )


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Result in Front Panel (heating)

XY Graph

R lt i F t P l ( li )


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Result in Front Panel (cooling)

XY Graph


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Thermistor

Thermistors are built with semiconductor

materialsand can have either a positive (PTC)

or negative (NTC) temperature coefficient.

However, the NTC is typically used fortemperature sensing.

NTC

Ad f h i i l d


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Advantagesof thermistorsinclude a very

high sensitivity to changes in temperature

(having a thermal response of up to -100/C at 25C),fast response time and

low cost.

The main drawback of thermistors is that

the change in resistance with temperature

is highly non-linear at temperatures below

0C and greater than 70C.


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Electrical Connections of Thermistor

A simple voltage divider is

created with a reference

resistor (R1) and the

thermistor (RT).

A constant voltage source

is supplied (VREF) with the

output of the voltage

divider (Vout)directly

correlating to temperature.


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The responseis shown in the graph of

temperature vs. output voltage to the right

of the circuit. It is fairly linear in the range of

0-70C.LINEAR

Why Use Thermistors To


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Why Use Thermistors ToMeasure Temperature?

They are inexpensive, rugged and reliable.

They respond quickly.

Thermistor Block diagram


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ThermistorBlock diagram

(Heating & Cooling)

Convert

temp(F) to (C)

T= ((1/298) +(1/4038)*ln(v/(5-v)))**(-1)*1.8-460 of


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Thermistor Front panel


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ThermistorFront panel

(Cooling)


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Real Picture

Thermistor


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AD590 Circuit

Solid State Temperature Sensor


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Solid State Temperature Sensor

(Linear 1 Microamp per Kelvin Output)

Solid state' temperature sensor has an easy to use linearvoltage output, unlike conventional resistive sensors.

TheAD590 is a small temperature transducer that converts a

temperature input into a proportional current output.

The advanced technology in the AD590is especially suited forspecial temperature measurement and control applications

between -55 and 150C (-67 to 302F) when solid statereliability, linearity and accuracy are required.

The sizeand responsiveness of the AD590 make it perfect foruses where size is a consideration, such as on PC boards or

heat sinks.


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Specifications

Absolute Maximum Ratings

Forward Voltage (E+ to E-): +44V

Reverse Voltage (E+ to E-): -20V

Breakdown Voltage

(case to E+ or E-): 200V Lead Temperature: 300C

Voltage Range: 4 to 30 Vdc

Nominal Current Output at 25C

(298.2 K): 298.2 A

Nominal Temperature Coefficient:

1 A/K

Calibration Error: J: 5.0C

maximum (K: 2.5C)

Absolute Error: Without external

Calibration Adjustment:

J: 10.0C max (K: 5.5C);

W/25C error set to zero J: 3.0Cmax (K: 2.0C)

Repeatability: 0.1C max

Long-Term Drift:

0.1C/month max


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AD590

The AD590 solid-state temperature sensor

produces an output of 100mV per degree

Celsius :

Temperature = Voltage * 100

For example we have 0.35(v) in 35(degree

Celsius).


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AD590- Front Panel


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AD590 Front Panel

(Heating)

AD590- Front Panel


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AD590 Front Panel

(Cooling)

Response temperature vs voltage


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(Heating)

R t t lt


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(Cooling)

Real Picture


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Real Picture

AD590

PT100


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PT100

The principle of operation is to measure the

resistance of a platinum element. The most common

type (PT100) has a resistance of 100 at 0 C and

138.4 ohms at 100 C. There are also PT1000 sensors

that have a resistance of 1000 ohms at 0 C.

The relationship between temperature and resistance

is approximately linear over a small temperature

range: for example, if you assume that it is linear overthe 0 to 100 C range, the error at 50 C is 0.4 C.


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Features

1. Extremely accurate.

2. Fairly good linearity.

3. Variety of packages.4. Wire wound or thin film.

l


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Applications

1. Industrial instrumentation.

2. Hot wire anemometers.

3. Laboratory quality measurements.4. Air , gas and liquid monitoring.

5. Petrochemical.

Real picture


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p

PT100

PT100-Block Diagram


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g

(Heating)

R=100(1+(t*0.00385))

PT100-Block Diagram


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g

(Cooling)

R=100(1+(t*0.00385))

PT100-Front Panel


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PT100 Front Panel

(Heating)

PT100-Front Panel


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PT100 Front Panel

(Cooling)

temperature vs. output voltage


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temperature vs. output voltage

(Heating)

Temperature vs. output Voltage(C li )


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(Cooling)


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