Ferry's total radiation pyrometer
Answers
Answer:
The total radiation pyrometer receives all the radiation from a particular are of hot body. The term total radiation includes both the visible and invisible radiations. It consists of radiation receiving element and a measuring device.
The mirror type radiation pyrometer is shown in figure below. Here, the
diaphragm unit along with a mirror is used to focus the radiation on a
thermocouple. The distance between the mirror and the thermocouple is
adjusted for proper focus. Here, the image of the front diaphragm is focused on the thermocouple by the mirror. Therefore, the temperature measurements are independent of the distance of the target
If there is any smoke, dust in the space between the tarhet and
transducer, it reduces the radiation. Hence negative errors. If there is any heat sources like hot gases and flames, then the meter reading will be high.
The characteristics of this pyrometer is non-linear. It has poor
sensitivity. This device is not used for temperature lower than 600 to 1200 degree Celsius. Output from this pyrometer is taken to pmmc instrument.
Explanation:
