How do you determine the minimum insertion depth of bimetallic thermometer?

Bimetallic thermometer is an instrument of measuring low temperature field in the temperature, it can directly measure - 50℃- All kinds of medium temperature 500 ℃. Its working principle is to put the two pieces of expansion coefficient difference is very big pieces of metal welded together. When the temperature changes, the difference is very big, caused the different expansion coefficient of expansion and contraction, the deformation of sheet metal bending. According to different deformation and produce different momentum, momentum to drive the connection shaft and the other end of the indicating needle, indicate the temperature. Understand the working principle of it, we can know, bimetallic thermometer inserted depth will directly affect its accuracy. As to how to calculate the minimum insertion depth of bimetallic thermometer? We can use a picture to look at. Different type, temperature range and heat pipe diameter together determines the minimum insertion depth of the bimetallic thermometer. Not less than a third ( Insert/total) , so the length of the heat pipe must be greater than the minimum insertion depth, to ensure the accuracy of sexual bimetallic thermometer.