Differential Pressure Air Tightness Tester: Principle and Applications

B. Differential pressure (also known as comparative) air tightness tester: There are two interfaces at the back of the instrument, one connecting to the standard product (qualified product) and the other connecting to the test product. 1) The instrument simultaneously fills the standard product and the test product with equal air pressure. Then the air source is cut off, and the difference between the air pressure in the standard product and the air pressure in the test product is observed. If the difference is zero, it means the test product is qualified; otherwise, the test product is not qualified. 2) If the product does not have an inflation hole, a volumetric differential pressure air tightness tester is used. Two sealing chambers of the same size as the product's shape and specifications need to be made. Then the instrument fills the space between the standard product and the test product with the mold with air pressure, and then cuts off the air source. The difference between the air pressure in the standard product and the air pressure in the test product is observed. If the difference is zero, it means the test product is qualified; otherwise, the test product is not qualified.