278 MECHANICAL ENGINEERING PRINCIPLES
- A platinum resistance thermometer has
a resistance of 24at 0°C. When mea-
suring the temperature of an anneal-
ing process a resistance value of 68
is recorded. To what temperature does
this correspond? Take the temperature
coefficient of resistance of platinum as
0. 0038 /°C(5) - State which temperature measuring
device would be most suitable to
measure the following:
(a) materials in a high-temperature
furnace in the range 1800°Cto
3000 °C.
(b) the air in a factory in the range 0°C
to 35°C.
(c) an inexpensive method for food
processing applications in the range
− 20 °Cto− 80 °C.
(d) boiler flue gas in the range 15°Cto
250 °C. (4)