An article by Marlene Langgutt & Martin Artner – asma quality control
For every order which leaves our company, a final inspection has to be carried out. Primary, the inspection serves the prevention of reclamations, which would cause additional costs. Thus, any order we receive and subsequently deliver is inspected in the most accurate manner. The batch size determines how many products need to be checked. The test statistics are defined in a so called sampling plan. For instance, the plan might require us to inspect three workpieces out of ten. Once this is defined, the most important measures like outer diameter, width, hardness, radius/chamfer and many more are determined according to each product. Additionally, the tolerance is specified, which may vary due to differing customer requirements (various specifications) or general tolerances. Furthermore, the product is inspected with regard to the production type or colour. Moreover, it needs to be determined whether the post curings were executed.
It is also quite important to use the correct measurement equipment:
An outer diameter with a tolerance level of ± 0.1 mm should not be measured using a calliper. If possible, for that special case a laser or an optical measuring device should be used, because they operate more precisely.
If the sample, which was measured, is in perfect condition, it is ready for dispatch. Otherwise, the sample size needs to be increased or post-processed, and if required, recoating needs to be conducted.