Optical Measuring Machine measures Seals until an Outer Diameter of 430 mm
In its second part the O-ring standard DIN 3771 prescribes that O-rings are to be measured contactless regarding the O-ring cross section, the number of measuring points however remains open. Considering the influence of the tool offset, meaningful data for the radial cord thickness can only be obtained by averaging as many single values over the entire perimeter as possible. According to DIN 2771 measurements with conical test mandrels and mandrels with different levels are allowed.
A measurement and sorting machine which was particularly developed for the measurement of O-rings has been commissioned by the O-Ring-Test-Laboratory Richter in September 1996. Through the combination of a line scan camera which is controlled by a linear drive and a rotatable glass measuring table it is possible to measure O-rings and also other seals with an inner diameter from 0 to 400 mm contactless very accurately. (Figure 1 and 2 depict the measuring principle for small and large o-rings. Bilder??) Besides outer and inner diameter, cord thickness or wall thickness can be measured.
A measurement and sorting machine which was particularly developed for the measurement of O-rings has been commissioned by the O-Ring-Test-Laboratory Richter in September 1996. Through the combination of a line scan camera which is controlled by a linear drive and a rotatable glass measuring table it is possible to measure O-rings and also other seals with an inner diameter from 0 to 400 mm contactless very accurately. (Figure 1 and 2 depict the measuring principle for small and large o-rings. Bilder??) Besides outer and inner diameter, cord thickness or wall thickness can be measured.
In comparison with already existing measurement machines out-of-roundness due to limpness of seals is not included as measurement error. Because of the evaluation of several thousands of measuring points over the perimeter and the following evaluation through a patent pending evaluation process a very good repeatability and a high accuracy of measurement is guaranteed by the contactless measurement of specimens. Besides the inner and outer diameter you get the average value and the selective minimum and maximum of the cord thickness as results. Up to an outer diameter of 25 mm it is possible to perform a test almost at one second intervals and due to a blowing device a sortation by good parts and bad parts can thereby be realised cost-efficiently. However, large seals can also be measured within seconds. Thereby – besides sortation according to precise tolerances – measurement reports can be compiled and statistic evaluations can be made with this newly developed O-ring-measurement-machine.