How to judge whether the refrigerant in the low temperature test chamber compressor is sufficient?

In the process of using low temperature test chambers, many users sometimes find that the refrigeration system has insufficient cooling capacity. When it starts running, it can still be cooled. After slowly cooling, the temperature will not drop. How to judge the refrigerant in the compressor? Not enough or other reasons? Now the small editor teaches you two ways to judge whether the refrigerant is insufficient.

First, the gauge pressure method: the low pressure side of the refrigeration system is related to the amount of refrigerant. The pressure gauge is connected to the low pressure valve, and the low temperature test chamber is turned on and off. At the beginning, the gauge pressure will drop. After running for more than 10 minutes, it is normal if the gauge pressure is stable at about 0.49 MPa.

Second, the current method: use a clamp-type ammeter to monitor the outdoor unit operating current (including compressor and fan current), if the current value basically meets the nominal current rating of the nameplate, indicating that the refrigerant is suitable; if it is less than the rated value, then the refrigeration Too little agent needs to be added.

The above two methods mainly use the results of current measurement, and also use the gauge method to determine whether to add refrigerant.