Temperature Sensors

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JAIPUR ENGINEERING COLLEGE & RESEARCH CENTRESubmitted by:-

Aditi Agarwal

ECE- A1

05

Submitted to:-

Prof. S.S. Shekhawat

TOSHNIWAL INDUSTRIES Pvt. Ltd.

A PRESENTATION ON

TEMPERATURESENSORS

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TOSHNIWAL INDUSTRIES Pvt. Ltd.• Founded in 1959 at Mumbai.

• Leading manufacturer of quality instruments in technical

collaboration with world reputed instrumentation companies

• It is an ISO 9001:2000 certified private limited company.

• The company was set-up at Ajmer (Raj.) under the supervision

of M/s Toshniwal Brothers Pvt. Ltd. (Estb. 1948) under the

leadership of renowned scientist, (Late) Dr. G.R.Toshniwal,

D.Sc.

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“It is time to turn up the heat

but first you must learn how to

measure it”

Temperature Sensor

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Types of Temperature Sensors

Thermocouple

RTD (Resistance Temperature Detector)

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THERMOCOUPLE

When 2 dissimilar metals are

joined together to form a junction,

an emf is produced which

is proportional to the

temperature being sensed.

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Seebeck Effect

The generation of current ina circuit comprising of twowires of dissimilar metals in

the presence of temperaturedifference.

The magnitude of emf depends on the junction temperature.

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Typical Industrial Thermocouple Assembly

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Types of ThermocouplesTCs are identified by a single letter type

and grouped according to their temperature rangeBase Metals – up to 1000 °C

Type J, Type E, Type T, Type K

Noble Metals – up to 2000 °C Type R, Type S, Type B

Refractory Metals – up to 2600 °C Type C, Type D, Type G

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Voltage to Temperature Curve

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Advantages:

Self Powered (does

not require a

current

or voltage source)

Rugged

Inexpensive

Simple

Disadvantages:

• Extremely Low

Voltage output

(mV)

• Not very stable

• Needs a

reference

point

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Resistance Temperature Detector- RTD RTD (Resistance Temperature Detector) is a temperature

sensitive resistor.

It is a positive temperature coefficient device.

The resistive property of the metal is called its resistivity.

The industry standard is the platinum wire RTD (Pt100) whose base resistance is exactly 100.00 ohms at 0.0 °C.

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Resistance v/s Temperature Curve

RTD

100.00

105.00

110.00

115.00

120.00

125.00

130.00

135.00

0 10 20 30 40 50 60 70 80 90

Temperature (∘C)

Re

sis

tan

ce

(Ω

)

RTD, the basics

• Traditionally made up

of platinum, nickel,

iron or copper wound

around an insulator.

• Temperature range:

From about -196°C

to 482°C.Thin Film RTD

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Platinum Scale ( 0 to 100 °C )

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RTD

Advantages:

Stable

Very accurate

Change in

resistance is linear

Disadvantages:

Expensive

Current source

required

Small change in

resistance

Self heating

Less rugged

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ConclusionIn TIPL, we have studied the working of

Electronics and temperature measuring

instruments of various schemes like Japan scheme,

English scheme, Inspection, Electrical

Maintenance including instruments such as

Thermocouple, RTD,

Wheatstone Bridge, Kelvin Bridge, Rheostat,

Light Spot Galvanometer .

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