ISO 6789-2:2017 pdf download.Assembly tools for screws and nuts — Hand torque tools — Part 2: Requirements for calibration and determination of measurement uncertainty.
The revision of Iso 6789:2003 has been designed to achieve the following improvements.
ISO 6789 has been split to provide two levels of documentation. It recognizes the different needs of different users of the standard.
ISO 6789-1 continues to provide designers and manufacturers with relevant minimum requirements for the development, production and documentation of hand torque tools.
This document 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.
The purpose of this document is to define the requirements for a calibration in which the sources of uncertainty are evaluated and used to define the range of values within which the readings probably fall. Additional uncertainties may exist in the use of the torque tool. The evaluation of uncertainties for each individual tool is time-consuming and where there are sufficient data to estimate the Type 13 uncertainty components by statistical means, it is acceptable to use these values for a given model of torque tool, providing that the uncertainty components arc subject to periodic review.
This document specifies the method for the calibration of hand torque tools and describes the method of calculation of measurement uncertainties for the calibration.
This document specifies the minimum requirements for the calibration of the torque measurement device where the relative measurement uncertainty interval, W’md, is not already provided by a traceable calibration certificate.
ISO 6789 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.
This document applies to hand torque tools which are classified as indicating torque tools (Type I) and setting torque tools (Type ii).
NOTE – Hand torque tools covered by this document are the ones identified in ISO 1703:2005 by reference numbers 6 1 00 11 0, 6 1 00 111 and 6 1 00 12 0, 6 1 00 12 1 and 6 1 00 14 0, 6 1 00 15 0. ISO 1703 is currently under revision. In the next edition, torque tools will be moved to an own clause, and with this change the reference numbers will also change and additional reference numbers will be added.ISO 6789-2:2017 pdf download.