The long way to reliable inline production measurement in metal wire products manufacture

摘要

Optical inline measurement is common in textile production, but not in the manufacture of some metal wire products using comparable techniques. The reason is that some ISO standards require highly precise measurements which are hardly feasible in the running production. Major factors for getting results of the aperture - the most important value in this respect - are the time needed to focus the camera, strong vibrations of the weaving machines as well as the light on reflecting surfaces and reference objects. Even in offline measurement, the comparability of the results is limited due to more restricted requirements especially in ISO 3310-1:2016 and ASTM E11-17 (test sieves). In these documents the conformity assessment methods have been updated on the basis of metrological recommendations. An ISO working group decided to pick up this issue and to look into the possibilities to improve the situation. That addresses the number of apertures to be measured, the coverage factors used as well as the overall statistics applied in the standard. Some research project are going to start accordingly in order to make the standards usable in the future.