The golden rule of measurement technology
The golden rule of measuring technology is a rule of thumb that states that the uncertainty of a measuring device should not exceed one tenth, in the extreme case one fifth of the tolerance . The golden rule helps with this indication when choosing a suitable for a specific measuring task measuring means .
background
In the interests of replacement , many identical components with the same nominal dimensions are manufactured. Despite all the precision, the desired nominal size is never achieved perfectly - there are always minor deviations. So that the function of each component can still be guaranteed, the nominal dimension to be achieved is given a tolerance. In quality assurance , which follows production, it is checked whether the actual size achieved is within the tolerance. The selection of the measuring device depends on the tolerance field width. With a very large tolerance, a very simple measuring device is sufficient. If the tolerance is very tight, very precise measuring equipment must be used. The golden rule helps at this point in choosing a suitable measuring device. The tolerance field width is divided by 10 and a measuring device is selected whose measurement uncertainty is slightly smaller than the calculated value.
If no measuring equipment is found that fulfills the condition of the golden rule, a suitability verification (e.g. measuring system analysis or measurement uncertainty analysis) must be carried out, which proves the suitability of the measuring device for the correct fulfillment of the measuring task.
history
The golden rule of measurement technology goes back to Georg Berndt , who formulated it between 1924 and 1930. In France, the rule was adopted shortly afterwards and was first called " règle d'or " (French for golden rule ). Although the exact influence of the measurement uncertainty on the residual tolerance was not yet known at the time the Golden Rule was drawn up, it had proven to be advisable at an early stage and has been established to this day as an initial assessment of the suitability of test equipment .
Individual evidence
- ↑ Georg Berndt, Erasmus Hultzsch, Herbert Weinhold: Functional tolerance and measurement uncertainty . In: Scientific journal of the Technical University of Dresden . tape 17 , no. 2 , 1968, p. 470 .