Pressure type thermometer structure and application

The principle of pressure type thermometer is based on the sealing temperature measurement system and saturated vapor pressure of liquid evaporation temperature, the change of the relationship between the temperature measurement. When the heat packs to temperature changes, saturated steam to produce the corresponding pressure in the closed system, cause the change of elastic element curvature, make its produce a shift in the free end, again by the displacement amplification mechanism of gear into the indicated value. Pressure type thermometer bulb small volume, fast response, high sensitivity, reading the characteristics of intuitive, set the glass rod thermometer, almost all the advantages of bimetallic thermometer, gas pressure thermometer, it can be made into shock, anti-corrosion type, and can realize remote contact signals, heat resistance, 0 10 ma, or 4 20 ma signal. Is currently the most widely use scope, performance is one of the most comprehensive mechanical thermometer table. Pressure type thermometer is the use of sealed container of liquid, gas or saturated steam heated volume expansion and pressure changes as the signal. Its basic structure is made up of bulb, capillary and indicator of three parts. It is one of the earliest methods of temperature control applied in the production process. Pressure type temperature measuring system now is still on the instructions and control is widely used in the temperature measurement method. Pressure type thermometer is: the advantages of simple structure, high mechanical strength, is not afraid of vibration. The price is low, does not need external energy. Defect is: limited temperature range, generally in - 80~400℃； Heat loss due to slower response time; Instrument sealing system ( Bulb, capillary, spring tube) Damage is difficult to repair, must be replaced. Measurement accuracy is influenced by environmental temperature, thermal package installation location is larger, accuracy is relatively low; Capillary transmission distance is limited, ability is limited. Pressure type thermometer have electric contact bimetallic thermometer and ordinary pressure type bimetal thermometer, they apply to measure all kinds of industrial occasions on which do not corrode copper and copper alloy liquid, gas, and steam medium temperature, and can work in temperature at or above the given value when the signal, the thermometer can also be used to contact switch circuit in the temperature control system. Cooperate with all kinds of casing installation, meet different pressure levels. Can be directly measured in the process of various - 80 ~ + 500 ℃ within the scope of liquid, steam and gas medium, as well as solid surface temperature measurement.