BS 7996-2009 pdf free download

BS 7996-2009 pdf free download.Torque measuring devices — Calibration and classification using continual torque application — Method.
required, to the torque measuring device without change ot the mounting position. The indicator reading may be tared to zero at the beginning of each measurement series. Record the output of the torque measuring device at the selected calibration torques.
5.2.3 The constant rate period shall be reached before the first torque data sample is taken.
5.2.4 Ensure that the maximum torque applied to the torque measuring device does not exceed 112% of the maximum calibration torque.
5.2.5 Within the constant rate period, it is permissible to increase the rate of application of torque between data samples provided the rate is lower than the maximum calculated value when readings are being taken and it can be shown that this increase of rate does not affect the measured values.
NOTE Two suggested methods of demonstrating this are: a) to ensure a time delay of the greater of 10’BTMD and 1O’8RS after the constant rate has to be achieved and before the reading is taken, and b) to ensure that the output from the torque measuring device is increasing at the same rate as the applied torque.
5.2.6 Record the output of the torque measuring device with zero torque applied before and after each application of a series of torques. The torque measuring device output may be tared to zero at the beginning of each measurement series.
5.2.7 Disturb and remount the torque measuring device in accordance with 4.6. After reconnection, load the torque measuring device once to maximum torque then apply and record the output of the torque measuring device during a further series of increasing torques.
5.2.8 Repeat 5.2.7 until torques have been applied at all required orientations.
5.2.9 Where relative reversibility is required, a single series of decreasing values shall be applied at the end of the last series of increasing torques.
5.2.10 The interval between successive application and removal of torques shall be as uniform as possible. For the determination of relative residual deflection, record the residual deflection reading not less than 30 s after the torque is completely removed.
52.11 Where the torque measuring device is required to be calibrated for both clockwise and anti-clockwise torques, follow the procedure given in 5.2.2 to 5.2.10.BS 7996-2009 pdf free download.