Thermometer


Definition of Thermometer

Thermometer is a device used for measuring the temperature.

More About Thermometer:


  • Different types of thermometers are used for different purposes.
    1. Example: Clinical thermometer is used to measure the human body temperature Six�s maximum and minimum thermometer is used to measure the temperature of atmosphere.
  • Different scales are used in different thermometers for measuring the temperature.
    1. Example: Centigrade Scale (100 divisions will be there on this scale. Lowest is 00 and highest is 1000)
  • Fahrenheit scale (180 divisions will be there on this scale. Lowest is 320 and highest is 2120).
  • Generally liquid metal mercury is used in thermometers. It expands (mercury thread) as the temperature rises and contracts (come close) when the temperature is decreased.
  • It consists of a glass tube on which the required scale is designed.
  • Every thermometer depends on some property of material that changes with the temperature.
  • All the thermometers agree at the fixed point (Freezing point and boiling point).

Example


What temperature is shown by the following thermometer reading?

    A. 500C
    B. 800C
    C. 420C
    D. 300C
    Correct answer is C

Some thermometer use materials whose electrical properties vary with the temperature.
    Example: Thermistor thermometer, Thermo couple thermometers.

Thermistor is a device which becomes a much better electrical conductor when its temperature rises.

Example


Which property is used in mercury � in � glass thermometer?.
A. Electrical conduction.
B. Electrical insulation.
C. Expansion Mercury.
    Step 1: Electrical conduction property is used in Thermistor type thermometer, so the choice "A" is wrong.
    Step 2: Electrical insulation property will not be used in any thermometer.
    Step 3: Expansion of Mercury on heating is the property which is used in mercury-in-glass thermometer.
Related terms: Temperature | Heat.
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