1) as far as possible using special instruments measurement method; (2) the use of hand push method measurement requirements of measuring higher measurement skills. This method of measurement error is large, especially when clearance of marginalized, easy to cause the error, at this time, should be the instrument measured;
(3) feeler, should be operated according to the provisions of the standard, shall not be used on the roller from the examiner rolling measurement methods of the past;
(4) the measurement process, should ensure that the ball fell into the ditch; closed type bearings in front of the closed measurement; when a Dutch instrument, measuring value should be less loading induced increase in clearance.
(5) for multi row bearing, the requirements of qualified each clearance, clearance from each column of the arithmetic mean as the bearing radial clearance.