An instrument used to measure temperature is known as Thermometer. The name was originated from two Greek words “thermos” which means “hot” and “metron” which means “measure”.

1. Types of thermometers and their properties

Thermometric properties and Types of thermometers

There are different types of thermometers used to measure temperature. A thermometer is specified by choosing a particular thermometric substance and a particular thermometric property of that substance. A thermometric property of matter is a property that varies predictably with an increase or decrease in temperature. It could be change of pressure in a gas thermometer, a change in electromotive force in a thermocouple, or the change in height of a liquid in a liquid thermometer. It is assumed that there is a one-to-one relationship between the measured values of that property and the temperature.