The judgment standard of air tightness testing equipment is the basis for judging whether product performance is qualified. Generally, relevant parameters obtained via bubble testing are formulated combining the product’s application scenarios, technical requirements, standards and corresponding processes. Different industrial products are equipped with distinctive sealing leakage standards.

The gas tightness tester adopts purified and dry air as the working medium to test the sealing performance of cavities with fixed internal volume. Series and parallel connection modes can also be applied for other testing tasks. However, it cannot directly test gas-liquid two-phase flow systems or gas-solid two-phase flow systems, otherwise inaccurate test results may be obtained and irreversible damage may be caused to the instrument.

How to select judgment modes for air tightness testing?

The system offers 7 judgment modes in total, including pressure drop judgment (Pa), pressure drop rate judgment (Pa/S, Pa/Min), flow judgment (ml/S, ml/Min), leakage rate judgment (Pa*ml/S) and mass judgment (g/year).

Pressure drop judgment: It is only related to testing time without calculating the workpiece volume. This mode is intuitive and suitable for mature products with long-term verified fixed empirical judgment values.

Pressure drop rate judgment: It eliminates the uncertainty of testing time. The pressure drop rate presents an approximately linear relationship within a fixed period, and there is no need to worry about the accuracy of volume parameter settings.

Flow judgment: It assumes that the leakage volume of the workpiece changes linearly within a certain period, so volume parameters must be taken into account. If workpieces have different volumes, identical pressure drop values under pressure drop mode do not mean the same actual volumetric leakage; larger workpieces have higher leakage rates.

Leakage rate judgment: It integrates the advantages of pressure drop rate judgment and flow judgment, representing the pressure drop per unit volume within a fixed time.

Mass judgment: It adopts the unit gram per year, mainly referring to helium testing parameters and incorporating the density coefficient of testing medium into calculation.