Length detection device for metering detection

A length detection device for metering detection comprises a main body, a sliding rail structure is fixedly installed on the surface of the main body, a sliding measuring disc is slidably installed in the sliding rail structure, a limiting plate is fixedly installed at the bottom of the sliding measuring disc, a sliding groove is formed in the circumferential surface of the sliding measuring disc, and a pressing block is slidably installed on the sliding groove. A mounting cavity is formed in the sliding measuring disc, a rotating rod is rotationally mounted in the center of the interior of the mounting cavity, a measuring belt is wound on the surface of the rotating rod, the tail end of the measuring belt extends to the exterior of the sliding measuring disc and is fixedly connected with a check block, and a first measuring arm and a second measuring arm are oppositely mounted in the main body. The non-linear measuring device can effectively measure the length of the edge or the surface of a non-linear measu