Study of Temperature Transducers

Study of Temperature Transducers .

• Temperature controlled oven with digital display
• Instrumentation amplifier with gain switching
• Digital voltmeter
• Interfacing circuits for common transducers

Introduction

Measurement of temperature is an important task in a large number of physical processes. A transducer in a device which converts the temperature information into an electrical signal, usually voltage, for an automated processing. A very wide variety of temperature transducers are commonly available which differ from each other with regards to there:

a) Range of operation

b) Sensitivity and linearity

c) Accuracy, Stability and Repeatability

d) Speed of response

The present experiments has been designed to study the input-output characteristics of some common transducers like, thermistors (PTC and NTC), thermocouple, semiconductor sensors and may be extended to also study the temperature coefficients of resistances.

The main requirements for an experiment of this nature are,

a) A precisely controlled from oven with a temperature display which is fast

b) An adjustable gain instrumentation amplifier which may be used to amplify the different levels of signals from transducers

c) Interfacing circuits suitable for the transducers used

Experiments

• Temperature-output voltage characteristics of the following transducers in the temperature range of room temperature to 150º C and determination of their parameters
• Chromel - Alumel thermocouple
• Copper - Constantan thermocouple
• Thermistors - Positive Temperature Coefficient
  - Negative Temperature Coefficient
• Semiconductor sensor (type AD590), upto 90ºC only

Features and Specifications

• Temperature controlled oven upto 150ºC with digital temperature display
• Digital voltmeter on the panel for sensor output measurement
• Built-in interfacing circuit and switched gain instrumentation amplifier
• IC regulated power supplies and detailed manual