Method for measuring light gap sealing of piston ring between photoreceptor and light source, involves determining whether application of force is subjected to joint area of piston ring at wall of control ring by optical unit

摘要

The method involves applying stress to extensive closure of shock portion (2) over a control ring (1') along the circumferential direction. A defined force (F) is exerted toward a wall of control ring in the region of pushing portions (5,6) of piston ring (3). An optical unit is provided to determine whether the application of force is subjected to joint area of piston ring at the wall of control ring. An independent claim is included for a device for measuring light gap sealing of piston ring.