The thermometer whose reading is indicated by a change in colour of its thermometric property is the?
-
A.
bi-metalic strip thermometer -
B.
thermocouple -
C.
platinium resistance thermometer -
D.
optical pyrometer
Correct Answer: Option D
Explanation
A pyrometer is instrument for measuring high temperature.
The optical pyrometer is one in which the luminous radiation from the hot body is compared with that from a known source.