| 摘要 |
PURPOSE:To assure inexpensively plural size reference standards of the same size by disposing single or plural numbers of reference piece groups having circular-arcuate reference planes having the same inside diameter on one holding body. CONSTITUTION:An annular hollow member 7 is hardened and is then worked with a round-shaped circular hole 7A of a prescribed size (R1) with high accuracy. The member 7 is divided into 16 segments along the circumference. Four reference pieces 4 are adhered and fixed in the holding groove 3 of a holding body 1, and the reference planes 5 of the pieces 4 are arranged on the circumference of the same inside diameter (R1). Three pieces among the four pieces 4 are disposed equidistantly at 120 deg. along the circumferential direction, and one is disposed apart from the other one at 180 deg. space. The plural size reference standards of the same size are thus inexpensively assured. |
