What are the methods for checking refrigerant leaks?

[Gandalf]

Methods for checking refrigerant leaks include: 1. Visual inspection method; 2. Soap bubble method; 3. Nitrogen water leak detection method; 4. Halogen leak detector method; 5. Gas differential pressure leak detection method. The steps for refrigerant charging are: 1. Prepare refrigerant that matches the required model; 2. Prepare qualified refrigerant charging tools; 3. Connect the car air conditioning system to the charging tool adapter; 4. Evacuate the system; 5. Charge the refrigerant. The properties required for refrigerants are: 1. Excellent thermodynamic characteristics to ensure high cycle efficiency within the specified temperature range; 2. High heat transfer coefficient, low viscosity, and low density; 3. Good miscibility with lubricating oil; 4. Safety requirements include being non-toxic, non-irritating, non-flammable, and non-explosive; 5. Good electrical insulation properties.