Abstract: Leak test equipment which includes a master side pneumatic system and a work side pneumatic system executes a leakage test sequence basically including pressurizing, balancing and detecting steps under control of a microcomputer. A nonvolatile read/write memory has prestored therein an equivalent inner volume of the work side pneumatic system corresponding to each type of work being tested for leakage. In a leak test, a leakage .DELTA.V.sub.L =V.sub.E .multidot..DELTA.P/1.03 is calculated on the basis of a pressure difference .DELTA.P between the work side pneumatic system and the master side pneumatic system, detected in the detecting step, and a corresponding equivalent inner volume V.sub.E read out of the nonvolatile read/write memory. The calculated leakage is compared with an allowable value of leakage, thereby deciding whether the work is acceptable or not.

Abstract: A predetermined number of preceding data items, which are obtained through measurement of change in pressure or pressure difference with respect to respective objects inspected and decided to be acceptable, are grouped according to types of the objects and stored in different storage regions. Each time new data is stored, the oldest data in the corresponding storage region is erased. An average of data stored in a designated storage region is computed and each object is decided if it is acceptable or not on the basis of the difference between the newly measured data of the object and the computed average of the data in the designated storage region corresponding to the object.

Abstract: A temporal variation in a fluid pressure of a fixed value applied to an article under inspection, or in the differential pressure between it and a fluid pressure applied to a comparison tank, is measured, and the measured value is compared with a reference value, thereby judging whether the airtightness of the article under inspection is good. Of the measured pressure or differential pressure data, data on the inspected articles judged non-defective are stored, by a predetermined number, in accordance with individual temperature differences between them and the comparison tank, or temperature differences between them a reference temperature, and a mean value of the stored data is calculated for each temperature difference. This mean value is used as a correction value for correcting, for each temperature difference, the measured pressure or differential pressure data on articles subsequently inspected.

Abstract: Pressure variation detecting type leakage inspection equipment which applies a fixed fluid pressure to an article to be inspected and judges whether the article is non-defective or defective, depending upon whether a change in the fluid pressure or in the differential pressure between the article under inspection and a comparison tank is within a prescribed value, data on pressure values or differential pressure values by respective measurement which are within a proper value range are stored in succession, the stored data are averaged to obtain a correction value, and data by each measurement is corrected by the correction value, thereby automatically correcting an error which varies owing to various factors. Thus a proper leakage inspection can be achieved.