What is a movable outer thread of bimetallic thermometer?

Bimetallic thermometer is a professional - measurement 50 to 500 c medium professional measuring instrument. Widely used in industrial equipment, petrochemical industry, heating system, piping, hvac equipment, power plants and Marine, etc. Common bimetallic thermometer is as follows: the bimetallic thermometer is a universal type, its header and connection mode of the heat pipe is through a 180 & deg; Rotating metal hose, it combines radial bimetallic thermometer and axial bimetallic thermometer features. What is moving outside thread in those metal thermometer? In fact, the movable external thread is the bimetallic thermometer and the measuring equipment interface connection. Common connection ways are: fixed screw, movable internal thread, moving outside thread and card sets, etc. So in bimetallic temperature time of choose and buy, be sure to understand the use of the bimetallic thermometer environment, especially interface with the device under test, so as not to cause unnecessary trouble.