Principle of thermal shock test chamber

       The thermal shock test chamber, also known as the three-box thermal shock test chamber, is mainly composed of a low temperature storage room, a high temperature storage room and an impact temperature test room. Knowing the operating principles of the three chambers of the thermal shock test chamber plays a vital role in how to operate scientifically and how to protect them 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 the comparison signal. The output signal of the meter PID logic circuit controls the time ratio of the solid state relay on or off Adjust the output power of the heater to achieve the purpose of automatic temperature control.

     (2) Low-temperature storage room: The temperature state in the box is determined by the operating state of the heater, evaporator and fan in the air duct. After the refrigerant throttling out of the expansion valve enters the evaporator in the operation room, it absorbs heat in the operation room and vaporizes, so that the temperature in the operation room is reduced; the vaporized working fluid is sucked in by the compressor and compressed into high-temperature, high-pressure gas into the condenser The medium is condensed into liquid, and then through the screening program, after throttling through the expansion valve, it re-enters the evaporator in the operation room to absorb heat and vaporize, and then is sucked and compressed by the compressor. Such a reciprocating loop operation makes the temperature of the operating room drop to the set temperature requirement

      (3) Impact temperature test chamber: The high and low temperature air valve is automatically controlled by the instrument, which switches between low temperature and high temperature storage rooms, and forms a closed circuit air circulation system with the high temperature box or the low temperature box respectively to quickly reach the target temperature of the test. 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" type circulating air operation, which can greatly improve the fluctuation, uniformity and other parameters of the equipment operation.