| 摘要 |
PURPOSE:To facilitate the monitoring of abnormalities such as the bending of the axis of a light beam and light source troubles, by arranging the light source and a light detector on both end sides of the body to be measured in the direction of the body to be measured and arranging a plurality of light detectors in parallel with the direction of the length of the body to be measured on the body to be measured. CONSTITUTION:A light source (a) such as a laser and a light detector Y are arranged on both end sides of the direction of the length of the body to be measured A such as pipe which is conveyed on a skid S. The detectors X1-Yn, which have a structure of a linear array and the like, are arranged in parallel with the direction of the length on the body A to be measured. The end surface boundary position of the body A to be measured, which is irradiated by the light source (a), is detected and the length of the body A to be measured is measured without contact. Since the detector Y is provided so as to face the light source (a), the abnormalities such as the bending of the axis of the light beam and the light source troubles can be readily monitored. |
