| 摘要 |
PURPOSE:To maintain high measuring accuracy for a long time, by tightening a thin wire, making the thin wire a reference point of measurement, and measuring the interval between the thin wire and a material to be measured separately by a plurality of pairs of light emitting and receiving elements, which are arranged in the longitudinal direction of the material to be measured. CONSTITUTION:Cut out parts 1a... are formed on the one side in the longitudinal direction of the surface plate 1 at a specified interval so that a steel pipe 2, which is a material to be measured, is mounted on a specified measuring position on a surface plate 1. V rollers 3, which convey the steel pipe 2 to the specified position on the surface plate 1, are provided in correspondence with the cut out parts 1a.... The surface plate 1 is supported so that is scan be moved up and down in the directions of arrows A and B. When the steel pipe 2 is brought to the specified position, the bottom surface of the surface plate 1 becomes higher than the upper ends of the V rollers 3. A tightened thin wire 4 is provided at a position separated by a length approximately equal to the radius of the steel pipe 2 along the longitudinal direction of the surface plate 1 at one side of the surface plate 1. A pair of laser emitting device and a laser receiving device are provided in each attaching frame 5, so that the laser light is emitted and received in the vertical direction with respect to the surface plate 1. |
