In fields such as automobiles, refrigeration equipment, electrical and electronics, energy, food, and pharmaceuticals, hermetic seals are used to keep the inside of products clean from the outside environment in order to maintain product quality. If unexpected micropores occur in the sealed parts during the manufacturing process, solids such as dust and bacteria, liquids including water, and gases such as water vapor and oxygen can come in or leak out, causing product defects. To avoid these undesirable situations, sealing inspections are conducted before reaching consumers. Sealing inspection methods include waterproofing tests, environmental testing, and leak testing. However, the results obtained from each test cannot be compared because the correlation between the results of these tests is still unclear, and the challenge is how to utilize the results of each test for efficient quality control. This is one of the factors preventing the transition from waterproofing tests, which visually check the amount of water intrusion, to more efficient and quantitative leak testing.

Researchers at AIST, in collaboration with the Japan Measuring Instruments Federation (JMIF), has been working with private companies, industry associations, and universities to develop an industry standard to confirm the reliability of sealing inspections. The result of this work was published on May 24, 2024 as JMIF 022 "Evaluation method and user’s guide for reference test piece for sealing inspection." In establishing this standard, AIST's research result, the "combined gas flow equation," was utilized.