RESISTANCE WELDING APPARATUS

摘要

Apparatus, for measuring the thickness of a welding seam produced by resistance welding between a resiliently mounted upper roll (10) and a lower roll (12), comprises a source of light (50) mounted laterally of the resiliently mounted roll and a light collector (54) mounted to receive such light as is not eclipsed by the periphery of the roll (10) so that variation in the amount of light received as the roll periphery interrupts the light is indicative of weld thickness. The light received is preferably converted by means (57) to an electrical signal which is analysed to discern the quality of the weld.