C. Choose the suitable measuring method
First is to make sure that the measurements used for which department, how to do, on these basis to choose reasonable benchmark. If the measured results to provide reference for adjusting the next procedure parameters, namely the measurement result is used to process adjustment, the measuring datum need to be unified with process datum; If measuring results used for assembly or for final acceptance of the work-piece, the measuring datum need to be unified with design datum. Design datum generally given in the drawing. The process datum is based on enterprise process, which is needed to confirm with processing personnel.
D. Check the accuracy and repeatability
To check the measuring machine state is whether normal or not, the method is simple. Use the standard check master to check the precision and repeatability, such as gauge block, sphere, ring gauge, square box and high precision grinding machine processing parts, etc., as long as issue the repeated measurement of length and diameter, then compare the measurement results with the theoretical standard size, if these readings and fit the dimensions of theory, and the repeatability is good, the measuring machine itself is without any problem, then continue to analysis the root cause of the problem from other aspects.
Please inform us if any questions or advice