Thermal shock test chamber, also known as the three-box hot and cold shock test chamber, is mainly composed of a low-temperature storage room, a high-temperature storage room and an impact temperature test chamber. Knowing the operating principles of the three chambers of the thermal shock test chamber plays a vital role in how to operate scientifically and protect reasonably.
  (1) High-temperature storage room: The central controller detects the real-time signal from the temperature sensing element, compares it with the set temperature signal, and obtains a comparison signal. The output signal of the instrument PID logic circuit controls the time proportional adjustment of the solid-state relay's turn-on or turn-off. The output power of the heater is adjusted to achieve automatic temperature control. ​
  (2) Low-temperature storage room: The temperature state inside the box is determined by the operating status of the heater, evaporator and fan in the air duct. After the refrigerant is throttled out by the expansion valve and enters the evaporator in the operating room, it absorbs heat in the operating room and vaporizes, lowering the temperature in the operating room; the vaporized working fluid is sucked in by the compressor and compressed into high-temperature, high-pressure gas and enters the condenser. It is condensed into liquid, then goes through the screening process, and finally is throttled by the expansion valve, and then re-enters the evaporator in the operating room to absorb heat and vaporize, and then is sucked and compressed by the compressor. Such reciprocating loop operation reduces the temperature of the operating room to the set temperature requirement.
  (3) Impact temperature test chamber: The instrument automatically controls the high and low temperature air valves, switches between low or high temperature storage chambers, and forms a closed-circuit air circulation system with the high temperature box or low temperature box respectively to quickly reach the test target temperature. The temperature status in the test chamber is determined by the operating status of the heater, evaporator, and fan in the air duct. The operation room of the test chamber adopts forced axial flow "dispersive" circulating wind operation, which can greatly improve the fluctuation, uniformity and other parameters of equipment operation.