DIN EN ISO 6789-2:2017-07

The standard DIN EN ISO 6789:2003:10 has been split to provide two levels of documentation. It recognizes the different needs of different users of the standard. DIN EN ISO 6789 now consists of the following parts under the general title "Assembly tools for screws and nuts - Hand torque tools - Part 1: Requirements and methods for design conformance testing and quality conformance testing: minimum requirements for declaration of conformance"; - "Part 2: Requirements for calibration and determination of measurement uncertainty". Part 2 of this series of standards provides detailed methods for calculation of uncertainties and requirements for calibrations. This will allow users of calibration services to more easily compare the calibrations from different laboratories. Additionally, minimum requirements for the calibration of torque measurement devices are described in Annex C in cases where the interval of maximum relative measurement uncertainty has not been determined by ISO/IEC 17025 certified calibration laboratories. This document is applicable for the step by step (static) and continuous (quasi-static) calibration of torque measurement devices, the torque of which is defined by measuring of the elastic form change of a deformable body or a measured variable which is in proportion to the torque. Furthermore, the following changes have been made: a) This document contains detailed methods for calculation of the uncertainty budget which shall be performed for each individual tool. b) This document includes example calculations that are provided for different types of torque tool. This German version has been prepared by Working Committee NA 121-05-01 AA "Schraubwerkzeuge, Fügewerkzeuge" ("Assembly tools for screws and nuts, Fastening tools") at DIN Standards Committee Tools and Clamping Devices (FWS).