The Gas Filled Dial Thermometer consists of a stem, capillary, and bourdon tube in a case. These parts are connected to form a unit. The complete measuring system is filled with an inert gas such as nitrogen, as standard, under pressure. A temperature change causes the internal pressure and volume in the stem to change.
The deflection of the bourdon tube thus caused is transmitted to the pointer by a movement. A bimetallic element is fitted in between the movement and bourdon tube to compensate for fluctuations of ambient the temperature at the case.
An extensive range of the standard version facilitates a variety of applications. In addition, special customized versions are also available.,under pressure.