|Diagram of radiation pyrometer.|
Explain radiation pyrometer:
What is radiation pyrometer? A device which measures the total intensity of radiation emitted from a body is called radiation pyrometer.
The elements of a total radiation pyrometer are illustrated in figure. It collects the radiation from an object (hot body) whose temperature is required. A mirror is used to focus this radiation on a thermocouple.
This energy which is concentrated on the thermocouple raises its temperature, and in turn generates an e.m.f. This e.m.f. is then measured either by the galvanometer or potentiometer method. Thus rise of temperature is a function of the amount of radiation emitted from the object.
Advantages of the pyrometers:
- The temperatures of moving objects can be measured.
- A higher temperature measurement is possible than that possible by thermocouples etc.
- The average temperatures of the extended surface can be measured.
- The temperature of the objects which are not easily accessible can be measured.