Gauge thermometers: Gauge thermometers are based on the principle that the volume of liquids, gases, or low-boiling liquids and saturated vapors in closed vessels expand or change in pressure after being heated, and the temperature is measured by measuring the change under pressure.
The pressure gauge thermometer is mainly composed of the following three parts:
1. The temperature packet - the temperature packet is directly in contact with the measured medium to feel the temperature change components, so it is required to have high strength, small coefficient of expansion, high thermal conductivity and corrosion resistance and other properties, according to the filling of the working medium and the medium to be measured, the temperature packet can be made of copper alloy, steel or stainless steel.
2. Capillaries -- These are seamless, round, cold-drawn tubes made of copper or steel to transmit changes in pressure.
3. Spring tube -- it is the general pressure gauge with the elastic element.
