초록 ▼

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 t

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.

대표청구항 ▼

In a leakage inspection method of the type wherein successive inspection cycles are performed each of which cycles includes a pressurizing procedure for applying an air pressure to an object to be inspected, followed by a balancing procedure for stabilizing the air pressure in said object, followed

In a leakage inspection method of the type wherein successive inspection cycles are performed each of which cycles includes a pressurizing procedure for applying an air pressure to an object to be inspected, followed by a balancing procedure for stabilizing the air pressure in said object, followed by an inspecting procedure wherein pressure measuring means are used to detect any change in pressure in the object a fixed period of time after completion of said balancing procedure, the improvement wherein said inspecting procedure comprises the steps of: zero-resetting an amplifier at the start of said inspecting procedure, said amplifier receiving a pressure signal from said pressure measuring means A-D converting the output from the amplifier by use of an A-D converter to produce currently measured pressure change data Di in a digital form; reading out a number of previously measured pressure change data up to a predetermined fixed number of such data from a selected one of a plurality of storage regions which are provided in a storage means, said storage regions corresponding respectively to different types of the object which are to be inspected, and said selected region corresponding to the type of object that is currently being inspected; averaging the measured data read out from said selected storage region to produce an average value Di; computing a difference di between the currently measured data Di and the average value Di; comparing the difference di to a limit value do; and when di is less than do, producing an accept signal and storing said currently measured data in the said selected storage region of said storage means.