The main principle used is that of the apparent thermal expansion of the liquid used. It is the difference between the volumetric reversible thermal expansion of the liquid and its glass container that makes it possible to measure temperature.

2. Department -Department of education and extension
Course-BSCBED(Integrated)
Name-Vaishnavi Vijay Raut
Subject-Heat and thermodynamics
Topic-Thermometry

3. Thermometry

4. Heat and temperature

5. Principles of thermometry

6. Temperature scales and Intervonversion

8. Types of thermometer:-
1.liquid thermometer
2.liquid filled thermometer
3.gas thermometer
4.bimetallic thermometer
5.resistance thermometer
6.thermocouple

9. • Liquid thermometers are based on the principle
that, a change in temperature is proportional to a
change in volume of liquid. ∆l ∆T. These thermometers
are suitable for narrow range of measurement of
temperature
Liquid thermometer

10. The filled thermometer is based on the principle of
thermal expansion i.e. there is fluid expansion due
to increase in pressure in a given volume of the
temperature measuring system.
Liquid filled thermometer

11. Gas filed thermometer works on the principle of Boyle's
w and Charles law le absolute pressure of a gas varies
directly with olyte semperature of volume remains
constant h is based on the cele that when the volume is
kept constant, the pressure of a gas cases with sie in
temperature according to the relation
Gas thermometer

12. A bimetallic thermometer is a temperature measurement
device.
It converts the media's temperature into mechanical
displacement using a bimetallic strip
Bimetallic thermometer

13. Resistance thermometers are a type of sensor used to
measure temperature.
Resistance thermometers work by changing resistance
with a change in temperature in a repeatable manner.
Resistance thermometer

14. The thermocouple working principle is based on the
Seeback Effect.
This effect states that when a closed circuit is formed
by jointing two dissimilar metals at two junctions.
junctions are maintained at different temperatures then
an electromotive force (e.m.f.) is induced in this closed
circuit.
Thermocouple