There are two detection methods for the air tightness tester:

1. Direct pressure (pressure drop type): The instrument fills the product with air pressure to see the change in gas pressure.

①. The test product has its own inflatable hole. The air tightness tester directly fills the product with air pressure. The instrument performs detection and observes changes in air pressure. A drop in pressure indicates that the product is leaking. Otherwise, it is a qualified product.

②. If the tested product is completely sealed and there is no air-filled hole, a volumetric direct pressure air tightness tester can be used to make a completely fitted sealed cavity according to the product size, so that the product is completely sealed by the upper cover and the lower module of the lamp. Inject air (compressed air source) into the product, and then the instrument will test it. According to the change of the leakage value of the air pressure charged in the man-machine interface, the pressure drop indicates that the product is leaking, and if the pressure does not decrease, it indicates that the product is qualified.

2. Differential pressure type (comparative type): The air tightness tester has two test ports, one is connected to the standard product (qualified product), and the other is connected to the test product.

①. The air tightness tester simultaneously fills the standard product and the test product with equal air pressure, and then the instrument performs the test. Observe the difference between the air pressure in the standard product minus the air pressure in the test product. The difference is zero, which means that the tested product is the same as the standard product, and it is a qualified product. On the contrary, if the internal pressure of the tested product is different from the internal pressure of the standard product, it means that the tested product is unqualified.

②. For sealed products without pores, a volumetric pressure difference air tightness tester can be used to make two sealed cavities that fully conform to the shape and size of the product (according to the size of the standard product and the test product). The product is completely sealed by the upper and lower modules of the fixture, the product inside the mold is filled with air (compressed air source), and the instrument is tested. Observe the air pressure of the standard product minus the air pressure of the test product. The difference is zero to indicate detection. This product is a standard product. On the contrary, if the internal pressure of the tested product is different from the internal pressure of the standard product, it means that the tested product is unqualified.