Choose bimetallic thermometer sheath to consider what factors?

Bimetallic thermometer is widely used in industrial equipment, we can often see that matchs with bimetallic thermometer using bimetallic thermometer sheath. Today let's say we choose bimetallic thermometer sheath to consider what factors. Can I know bimetallic thermometer sheath is mainly to protect the action of bimetallic thermometer sheath maerial. So we should consider when choosing a bimetallic thermometer sheath three factors. The first is the material, be sure to choose SS304 or SS316 material, these two material is durable, if material is bad, often need to change the sheath is not convenient; The second point is the bimetallic thermometer sheath of the specifications of the female and male must ask clear, or it will affect the installation; The third point is the length of the heat pipe, the length of the heat pipe and the specifications of the internal thread, matching the length of the bimetallic thermometer heat pipe. Eventually, of course, choose what kind of bimetallic thermometer sheath or according to their own actual situation.