2、 Liquid expansion thermostat: it is a physical phenomenon (volume change) that causes the material (generally liquid) in the temperature sensing part of the thermostat to expand and contract correspondingly when the temperature of the controlled object changes, and the capsule connected with the temperature sensing part will expand or contract. Based on the lever principle, it drives the on-off action of the switch to achieve the purpose of constant temperature. The liquid expansion thermostat has the performance characteristics of accurate temperature control, stability and reliability, small start-up and stop temperature difference, large control temperature control adjustment range, large overload current and so on. Liquid expansion temperature controller is mainly used in temperature control fields such as household appliance industry, electric heating equipment and refrigeration industry.
3、 Change the pressure of the working medium and the volume of the controlled device to the instantaneous temperature, and achieve the purpose of automatic temperature control through the change of the pressure of the controlled device and the volume of the working medium. The utility model is composed of a temperature sensing part, a temperature setting main body part, a microswitch for opening and closing or an automatic damper. Pressure temperature controller is suitable for refrigeration appliances (such as refrigerator, freezer, etc.) and heating devices.
4、 Electronic temperature controller and electronic temperature controller (resistance type) are measured by resistance temperature sensing method. Generally, platinum wire, copper wire, tungsten wire and thermistor are used as temperature measuring resistors. These resistors have their own advantages and disadvantages. General household air conditioners mostly use thermistor type.