When the ambient temperature around the thermometer changes, the liquid in the indicator and capillary will expand or contract correspondingly, and the indication error will be generated. The following two compensation methods can compensate for this error.
a. Bimetallic compensation：①Measure actual temperature ②Measure ambient temperature
It is suitable for the condition that the ambient temperature around the indicator and the wire changes in the same way
b. Catheter compensation
Suitable for independent change of ambient temperature around indicator and conductor
* The temperature around the indicator changes very little, while the temperature around the conductor changes a lot.
* Each part of the conductor is under different ambient temperatures
* Part of the wire is heated