RTDs are used to measure temperature in a process stream because they have many distinct advantages over thermocouples, including higher resolution of measurement, are more stable, are more repeatable, and give a more linear measurement response.
However, RTDs have some distinct disadvantages as compared to thermocouples. All of the following are disadvantages of RTDs as compared to thermocouples, except:
A. Require a temperature transmitter to function
B. Must have equal length and same type and gauge of lead wires
C. Are not self-powered
D. Are more expensive than thermocouples