There are two types of thermal shock test chambers: two-zone and three-zone test chamber. According to the media classification, there are three types of liquid test chamber, gas test chamber, and ice water test chamber.
Here we mainly explains the three-zone thermal shock test chamber, which is mainly composed of a low-temperature storage zone, a high-temperature storage zone, and an test zone. Knowing the operating principles of this type of chamber can assist us in scientific operation and reasonable maintenance.
Test zone：The instrument automatically controls the high and low temperature air valves, switches between low temperature or high temperature storage zone, and forms a closed circuit air circulation system with the high temperature chamber or low temperature chamber, quickly reaching the target temperature for the test.
High-temperature storage zone：The central controller detects the real-time signal from the temperature sensor, compares it with the set temperature signal, and obtains a comparison signal. The PID logic circuit of the instrument outputs a signal to control the turn-on or turn-off time ratio of the solid-state relay, and adjusts the output power of the heater to achieve automatic temperature control.
Low-temperature storage zone：the temperature status in the zone is determined by the operating status of the heater, evaporator, and fan in the air duct. The refrigerant flowing through the expansion valve throttle enters the evaporator in the zone, absorbs heat, and vaporizes, reducing the temperature in the zone; After gasification, the working medium is sucked in by the compressor and compressed into high-temperature and high-pressure gas, which is condensed into a liquid in the condenser. After passing through a screening program and being throttled by an expansion valve, it enters the zone again for heat absorption and gasification, and then is sucked in and compressed by the compressor. This reciprocating operation reduces the temperature of this chamber to the set temperature requirements.
