1. Basic principles:
The acceptance method used should only accept workpieces that are within the specified size acceptance limits. For the workpieces with matching requirements, the dimensional inspection should comply with the Taylor principle, and the effective size of the hole or shaft must not exceed the maximum physical size.
Note: The Taylor principle is that the holes and shafts with matching requirements, the local actual size and shape errors must be controlled within the dimensional tolerance band (shaft minus hole plus).
Second, the principle of minimum deformation:
In order to ensure the accuracy and reliability of the measurement results, the deformation caused by various factors should be minimized.
Third, the principle of the shortest dimensional chain:
In order to ensure a certain measurement accuracy, the link of the measurement chain should be minimized, that is, the measurement chain should be the shortest (to reduce the accumulation of measurement errors).
Fourth, the principle of closure:
In the measurement, if the closing conditions can be met, the sum of the interval deviations is zero, which is the closing principle.
Fifth, the unified principle of benchmark:
The measurement reference should be consistent with the design reference and process reference.
Add: Shenzhen, China