There is difference between radiation pyrometer and optical pyrometer is given below.
|Temperature is direct measured with the help of thermocouple.
||Temperature is measured by comparing the brightness of hot body radiation at specific colour.
|Emissivity of target may affect measurement.
||Dust, smoke and thermal background radiation affect.
|Chance of error is negligible.
||Causing human error.
|The radiation pyrometer has moderate cost.
||The optical pyrometer has high cost.
|The output is directly given by thermocouple in terms of m volt.
||The output is observed by human eye.