Al Case Gas filled Temperature Gauge(AT)
The AT model thermo consists of stem, capillary and bourdon tube in a aluminum case. These parts are connected to form a unit. The complete measuring system is filled with an inert gas as standard or mercury as an option under pressure. A temperature change causes the internal pressure 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 moment and bourdon tube to compensate for fluctuations of ambient temperature at the case.