In numerous application it is neither desirable nor proactical to expase a temperature sensor directly to a process i = material Wells are therefore used toprotect against damage corression, arosion, abrosion and high pressure processes. A thermowell is also useful in protecting a sensor from physical damage during handling and normal operation.

Selecting a thermo well :
The significant properties considered in nelecting a material for the well are as follows :
1. Resistance to corrossion and oxidation.
2. Resistance to mechanical and thermal shock.
3. Low permeability ( Resistance to gas leakage ).
4. Mechanical strength.
5. Thermal conductivity.

Material for Wells :
1. Stainless steal.
2. Inconel.
3. Monel.
4. Alloy steal.
5. Hastelloy 'C'.   _{Your Comment}