1. First of all, prepare special tools for maintenance, such as (digital multimeter, test pen, typesetting screwdriver, needle-nose pliers, vacuum pressure gauge, B-12 gas cylinder, refrigerant, filling tube, welding tools, etc.).

2. Check whether the exhaust pipe of the dry filter device is normal;

3. Check whether the working pressure indication of the vacuum pressure gauge drops, and whether it is in the working state of the vacuum pump. If there is no such situation, stop the machine immediately, check whether the pipeline, air storage tank, and air pressure gauge are connected properly, and whether the air intake air pressure gauge is in the state of the vacuum pump, or the welding is blocked due to poor welding.

4. After finding out the cause and detecting the fault, the power can be reconnected for observation. Using this method to exhaust the pipeline of the constant humidity chamber can only remove most of the gas in the capillary tube, air conditioning evaporator, breathing tube, and refrigeration compressor in the system, and cannot achieve the purpose of the system aspect ratio vacuum pump.