How to measure the pressure value and refrigerant of the high and low temperature test chamber

When the high and low temperature test chamber cannot be opened at ultra-low temperature, it will be caused by the following reasons:

1. The refrigerant volume of the refrigeration unit is not enough (fluorine leakage).

2. The pipes of the refrigeration unit are blocked by dirt or ice.

3. The relay supplying liquid to the air conditioner evaporator is damaged.

4. The total flow of the air conditioning expansion valve is too large or too small or damaged. Check whether the high and low temperature test chamber is lack of refrigerant. If the refrigerant is not enough, consider adding refrigerant.

Operation process of high and low temperature test chamber plus refrigerant: firstly, select the matching refrigerant according to the model and specification of different refrigeration compressors. Refrigerant includes R404, R23, etc. Then find out the corresponding volatilization working pressure according to the volatilization temperature of the refrigerant, connect the air outlet of the refrigeration compressor of the high and low temperature test cycle system tester with the refrigerant vessel, open the high and low temperature test cycle system tester, connect the composite meter, and open it to check the working pressure. According to the working pressure value of the barometer, it can be determined whether the refrigerant charge is appropriate.

If the working pressure value of the high and low temperature test chamber is insufficient, the targeted refrigerant must be added. Before adding refrigerant snow seed, remove the gas, loosen the green water pipe of the bottom pressure pipe, then open the cylinder of refrigerant, use refrigerant to expel the gas, and then tighten the gate valve of adding refrigerant snow seed. In the whole process of adding, you should pay attention to the barometer. If the working pressure is full, you can turn off the refrigerant green regulating valve. Regardless of the model and specification of the refrigeration compressor, the way to add refrigerant is similar.