The pressure drop method is used for detection. The changes of gas pressure and volume are detected through equal intake, pressure stabilization and detection. The leakage rate and leakage value are obtained by the air tightness detector through a series of sampling, calculation and analysis. According to these data, judge whether it is OK or NG.

Waterproof test for auto lamp，Instrument belongs to a type of key operation, set up the test parameters to press the start button after the instrument is up and running, automatic monitoring of product testing, testing process can be real-time monitoring on the instrument interface testing, testing after the completion of the indicator light for "OK" or "NG" will light up lights, test results show that on the home page, and automatic data storage,  Facilitate historical query of product test results.

Auto Lamp Air Tightness Testing Machine to be tested are generally headlamp, tail lamp, turn signal lamp, license plate lamp assembly and headlamp shell.