Abstract
This paper describes some experiments with the personal error of micrometers caused by operational process. In the evaluation of the performance of micrometers, YANO et al. pointed out that measuring error analyzed on an experimental planning method exceeded "overall error stipulated in JIS B 7502" in the case of the unskilled. This error was thought to be due to the operational process of ratchet stops. A new method with small load cell between spindle and anvil faces without play enables one to measure the measuring forces of micrometers far more accurately. Main results are as follows: (1) A noticeable linear regression relations are found out between measuring forces and rotational speeds of ratchet stops just before the collisions of the spindle faces with measuring objects. (2) The variations of rotational speeds of ratchet stops by operators cause those of measuring forces about from 6 to 50 N (0.6 to 5 kgf) and those of readings over 10 μm based mainly on the deformation of the frame.
