LENGTH MEASURING DEVICE

PURPOSE:To eliminate the need for correcting the abrasion of rails, wheels, etc. over a long period of time in a device for measuring length from the moving distances of length measuring carriages by detecting the inclinations of the carriages and correcting the moving distances. CONSTITUTION:A pair of right and left length measuring carriages 13 are provided on a guiding rail 12, and end part detectors 19 are supported on the carriages. When a pipe 24 which is an object to be measured rides on supporting frames 25, the motors 14 on the respective carriages start running and the carriages are moved from the end parts of the rails in arrow directions; at the same time, distance pulses are transmitted from moving distance transmitters 15. The overall length of the pipe is calculated from the integrated distance pulses until the end part detectors detect the end parts of the pipe and the overall length of the rail. Inclination signal transmitters 16 detect the angles of inclination of supporting rods 17 when the end parts detectors detect the pipe ends. In accordance with the detected angles of inclination, the errors of the carriage moving distances are calculated and the distances are corrected.