Verification of the calipers display accuracy

In advanced machine building, when manufacturing parts, it is imperative to control their geometric accuracy. Many measurements are made using calipers. It is important to make sure that the measuring devices meet requirements on the established accuracy, as this affects the measurement accuracy and, consequently, the quality of the product. Therefore, in the context of machine-building enterprises, it is necessary, according to established procedures, to verify the accuracy of devices, in particular, to check the indication of calipers. However, in current regulatory literature, methods for checking the indication of calipers are given in general terms, and the operator has to solve some of issues related to the accuracy verification on his own. Thus, machine-building enterprises need to have clear and understandable procedures for assessing the accuracy of devices in operation.The article presents the theoretical analysis of regulatory documents and experimental studies that allowed us to develop practical recommendations on the verification procedure of the accuracy of calipers' indication, in particular, the choice of control points, the number of repeated measurements, and the decision on whether the device meets or does not meet the specification. The developed recommendations will reduce the time for checking the accuracy of the caliper indication, which, in turn, will reduce the cost of verification calipers and improve the quality of inspection of parts.Thus, it can be noted that the developed recommendations can reduce time and cost of the procedure for verification the accuracy of calipers' indication, which, in turn, will lead to the increase in the quality of control of machine parts in their manufacture, due to the absence of incorrectly defective and incorrectly valid parts.