The allowable deviation between the preset or adjusted torque values must be inside of the tolerances as defined by the DIN EN ISO 6789 International Standard or the relevant National Standard.
Torque wrenches: proper characteristics and function
A torque wrench must be able to fulfill a variety of tasks. The ability to measure and verify fixed or varying torque values is just the beginning. Given the vast arena of possible operational environments a torque wrench should not only be precise but robust and easily adaptable to a wide variety of fastening applications.
An ever-increasing importance and value is being laid on increased accuracy and the ability to document the measurements being made. These higher requirements can be met with an advanced electronic torque wrench which can provide not only a high level of accuracy but also the ability to store, administer, and provide a platform for additional evaluation of the measurement settings and results.
In order to assure that a torque wrench is capable of functioning within the required level of accuracy, it must be calibrated at regular intervals.
Calibration is often mistaken for the adjustment of a torque wrench. The calibration of a torque wrench is in simplest terms the operational comparison of measurements between a subject torque wrench against a master which is traceable to a known standard. The accuracy deviation also needs to be measured multiple times at several predefined locations if the torque wrench has an adjustable range to determine the overall deviation accuracy.
DIN 51309 further defines a process to calculate the calibration procedures measurement uncertainty. A periodic basic accuracy check of a torque wrench can take place between regular calibration intervals with the use of an appropriate and calibrated tester. The calibration of a torque wrench at regular intervals of time or usage in a nationally or internationally accredited calibration laboratory is of absolute importance. The accreditation of the laboratory by a National Authority in accordance to the DIN EN ISO 17025 standard (or equivalent) assures traceability compliance in accordance to the DIN EN ISO 9001 standard. AMT
Some tips on proper torque wrench procedures Joe Escobar Torquing hardware is an everyday occurrence. In our day-to-day routine, numerous tasks are performed that require a specific torque...
Norbar manufactures an extensive range of high quality torque wrenches to cover torque values from 1 N.m to 1,500 N.m. They are designed and manufactured to exceed international standards for...
Norbar manufacture an extensive range of high quality torque wrenches to cover torque values from 1 N.m to 1,500 N.m. They are designed and manufactured to exceed international standards for accuracy...