The IP dustproof and waterproof rating defines the level of protection that mechanical and electronic equipment can provide to prevent solid foreign objects (including fingers, dust, sand and other body parts), liquid penetration and accidental contact. It is usually represented by IP plus two digits. The first digit indicates the dustproof ability, and the second digit indicates the waterproof ability. The larger the number, the stronger the ability.

For the water-proof performance of outdated test products, the more traditional method is to use water test. This method is undoubtedly the most reliable method, but various shortcomings such as low efficiency, component contamination, subjective judgment and inability to measure leakage values ​​make it unsuitable for batch inspection and precise inspection in factory online production. At present, most of the batch online inspections for waterproof testing of electronic factory products use differential airtight leak detectors.

The airtight leak detector uses compressed air as the detection medium, and fills the detection end and the standard end (completely sealed) with a certain gas pressure. After a period of balance, observe the pressure change. At the detection end, if there is a leak in the detected workpiece, reduce the pressure at the detection end, and then the airtight leak detector reads the pressure change through the differential pressure sensor, and passes a series of algorithms (effectively eliminates deformation, temperature, etc.), Judge the amount of leakage. According to the judgment standard, judge whether the workpiece is qualified.

When using the airtight leak detector, we can convert the water pressure to air pressure for testing according to the requirements of the IP rating standard. For example, the waterproof requirement of IP67 is a distance of 1 meter underwater, and the detection pressure of 10-15kPa is required for the detection of an airtight leak detector. For higher-level IP68 tests, manufacturers need to formulate specific test requirements, but the test pressure must be greater than 10-15kPa.