The principle, structure and advantages and disadvantages of pressure type thermometer

Pressure type thermometer we are familiar with, its principle is: based on the sealing temperature measuring system of liquid evaporation changes in the relationship between saturated vapor pressure and temperature, and temperature measurement. When bulb feel temperature, saturated vapor produced the corresponding pressure in the closed system, cause the change of curvature elastic element, make its produce a shift in the free end, again by the displacement amplification mechanism of gear into the indicated value. Pressure type thermometer basic structure is composed of the basic structure of the 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. The advantages and disadvantages of pressure type thermometer advantages: simple structure, high mechanical strength, is not afraid of vibration. The price is low, does not need external energy. Disadvantages: limited temperature range, be in commonly - 80~400℃； Heat loss due to slower response time; Instrument sealing system ( Bulb, capillary, spring tube) Damage is difficult to repair, must be replaced. Measuring accuracy are greatly influenced by environmental temperature, temperature package installation location, accuracy is relatively low; Capillary transmission distance limit.