ABSTRACT
Temperature scales aim at using a common basis for temperature measurements. All temperature scales are based on some easily reproducible states, such as the freezing and boiling points of water, also called the ice point and the steam point. A substance used for the measurement of temperature must experience some recognizable change when its temperature is changed. The Beckmann thermometer is used for the accurate determination of small temperature change, such as that encountered while using the bomb calorimeter. Temperature measurements based on electrical effects such as change in resistance with temperature have become popular because they are very convenient techniques and they furnish a signal that is easily detected, amplified, or used for control purposes. High temperature can spoil the thermocouple wire insulation. The resistance of the insulation decreases exponentially with increasing temperature, even to the extent that it creates a virtual junction. Temperature can also be measured using resistance temperature detector devices.
