Negative pressure leak test machine is strange to everyone. In fact, it is a equipment that performs IPX8 waterproof inspection on the outer casing of the product through the principle of negative pressure detection. It is differ from the traditional water immersion tank, the leak points can be found during the test. The pressure leak test machine is consisted by Sealed jar, control units, stainless steel shell and so on, the working principle is to use the vacuum pump to draw out the air of water surface, so that there is a pressure difference between the inner cavity and the outer cavity of the sample. At the time, two situations may occur: if the sample is a defective product, bubbles will continuously appear in the water, and the bubbling position can be observed through the transparent tank; if the sample is a good product, no bubble is emitted.

The operation steps as below:

1. Well connect the power source, water source and air source. Add the water into the tank till to 2/3 position, but not exceed the sample tray.

2. Fixed the sample at the center of the tray.

3. The test depth can be set between 1m to 8m, the test time and leak time can be set according to the sample between 1s to 999s.

4. When the test begins, the equipment vacuums the space where the sample is placed firstly. After the rated value is reached, the tray sinks into the water to start pressure relief. During the pressure relief process, the sample is simultaneously observed for leakage and the leak point is recorded.

5. After the test is completed, it will automatically stop and alarm, and the tray will rise and the sample will be taken out.

The pressure leak water immersion tank treats the sample by vacuum. If there is a leak, the pressure inside and outside are consistent. During the pressure relief process, the leak point is exposed. This test method is suitable for small samples and is suitable for use in various laboratories.