Method for optical-scanning examination of wheel tread of train, involves changing distance between view position and scanning position such that length of wheel tread surface is set larger than focus depth of optic portion

摘要

The method involves aligning a scan direction (R) of a scanning optic portion (10) to a fixed point of view position in a scanning view (1) spaced from a scanning position (AP) on a wheel tread (303). The focus distance (2) of optic portion is adjusted on scanning position for optical scanning and signal detection. The distance between view position (SP) and scanning position is changed around specific value of wheel tread such that a peripheral portion of wheel tread is detected and length of wheel tread surface is set larger than the focus depth of optic portion. Independent claims are included for the following: (1) an optical testing apparatus; (2) a test system; (3) a test system arrangement; and (4) a control module.