BS 7996 is a safety standard on torque measuring devices.
BS 7996 specifies a method for the calibration and classification of torque measuring devices using continuous torque application where the inertial effects are minimal. BS 7996 includes torque measuring devices used for the calibration of torque tools.
BS 7996 provides diagrams of the continuous application of torque and examples for the calibration of torque measuring devices. BS 7996 also gives an example of determining the uncertainty of the calibration results of the torque measuring device. BS 7996 shows how to calculate mechanical and electronic bandwidth.
BS 7996 on the calibration and classification using continual torque application is relevant to:
Torque measuring devices are used to measure torque in rotating parts of machines, torque of rotating shafts.
BS 7996 describes a method of calibration and classification. BS 7996 introduces the relative measurement uncertainty interval, the range in which the expected error is likely to lie, calculated as the sum of the absolute relative deviation and the expanded uncertainty. BS 7996 assists the user with the sequence consisting of three time periods: acceleration period, constant rate period, and deceleration period. BS 7996 also assists with loading direction, the lower limit of calibration, maximum calibration torque, rate of applied torque, and other distinct types of methods of calculation.
BS 7996 also specifies bandwidth. Bandwidth is the range of frequency, over which the performance of the electronics processing and the sensor maintains accuracy as required. Bandwidth is especially relevant to amplification of the torque signal or any conversion device such as an analogue-to-digital converter or a digital-to-analogue converter. BS 7996 also helps in classifying torque measuring devices.
Overall, BS 7996 is useful as it provides guidance on carrying out checks and settings of the instrumentation in accordance with the manufacturer’s information, where available.