The principle of pressure type thermometer and use requirement

Pressure type thermometer is, according to a gas or liquid temperature in the bag made of the nature of the change of pressure because of the heat. Generally divided into two indicating and recording. The former can be read directly from the dial on the temperature values, the latter has a recording device, can record the temperature of different time value. Mainly by the header, metal hose and artifacts such as bulb. Wen bags containing volatile hydrocarbon liquids. Measuring temperature, the temperature of liquid heated evaporation, and along the capillary to the header in the metal hose. The structure of the header and bourdon tube type pressure gauge, the same size of a pointer deflect Angle on the header is proportional to the temperature of the measured medium, namely the pointer in the reading on the dial is equal to the temperature of the measured medium. Pressure type thermometer is suitable for long distance measuring the corrosive gas, steam or the temperature of the liquid, the measured medium pressure no more than 5. 88 mpa, temperature does not exceed 400 ℃. In industrial boiler is used to measure air temperature of the air preheater. It has the advantage of temperature indicating part can leave the station, easy to use. Defect is low precision, metal hose is easy to damage. Install and use requirements of the pressure type thermometer 1) Pressure type thermometer meter should be installed in easy reading. Headers and metal hose working environment temperature should not be more than 60 ℃, relative humidity should be between 30% ~ 80%. （ 2) Laying metal hose shall not be close to hot surface or temperature change is big, and should try to reduce the bending, bending radius not less than 50 mm. External should have full protection, in order to avoid mechanical damage.