UsuallyAir tightness testingThe most commonly used method is pressurization or vacuuming, and there are indeed many methods for air tightness testing, ranging from very simple waterBox method to very complex gas detection method, a brief introduction is as follows:

Foam method: Apply soap solution to the surface of the part, add air pressure, and observe the bubbles.

Air/水法：对零件封堵，充入一定压力的空气，待气体稳定后测定压降，根据压降值判断密封性，This is the method most suitable for application in industrial production and can be tested online.

Gas detection method: for some cases where air cannot be used / The field of air law (such as small leakage, large volume, need to know the leakage point), gasVolume detection method, however, factors such as high gas cost and slow testing limit the large-scale use of this method.Commonly used gas detection methods includeTwo types:

(1) Place the part under test in a detectable situation, evacuate, and determine the amount of leakage of the part under test based on the amount of gas entering the detector.

(2) Fill the inside of the tested piece with detection gas, and then detect the leakage point and evaluate the size on the outside.The detection limit of this method depends on the gasbody and detector.Many gases can be used, the most commonly used is halogen gas, and the most sensitive one is Freon.

Measurement based on gas pressure changes is more and more widely used in industrial production.Due to its simple application and high degree of automation,It has relatively low cost, fast speed and high precision, so it is very suitable for equipment in workshops and automatic production lines.