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.