PURPOSE: To contrive high precision and efficiency of inspection by detecting a difference between each separation distance between each pair of a displacement detector and a detection plate in each group on a flange part or/and an average value thereof.
CONSTITUTION: A main cylinder 2 is started, its actuation rod 3 is lowered, a press member 7 is moved down in the direction of a horizontal mounting base 1, its lower end part 7c is brought into contact with a flange part 11 of a plastic vessel 10, and in a condition in which the press member 7 presses the flange part 11 by its dead weight the main cylinder 2 is stopped and lowering of the member 7 is suspended. Signal data equivalent to separation distances D1, D2 between a displacement detector 8 and a plate to be detected 9 are detected by means of detection signals with which the detectors 8, 8 serve to detect the two opposed plates to be detected 9, 9 and a deformation condition or/and an average thickness of the flange part 11 are inspected.
WADA KIYOSHI
KAGEYAMA MASAYUKI
