1, as far as possible using special instruments to measure law;

        2, using the method of measurement requirements push higher surveyor measuring skills. When this method is the measurement error is large, especially in clearance at the edge of the state, prone to error, this time, the instrument should measure shall prevail;

        3, feeler, standard provisions should operate, must not use the previous method to measure roller feeler from the roll;

        4, the measurement process, should ensure that the ball fall into the ditch; closed bearing measurements before closing; When using the instrument has a load, the measured value minus the gap should increase the amount of travel loads.

        5, for multi-row bearings require clearance pass each column, each row arithmetic mean clearance as bearing radial clearance.