Final Report on Torque with Cross Force Comparison No. MT01 ...

<strong>Final</strong> <strong>Report</strong> of MT01deviation in %0.0-0.2-0.4-0.6-0.8-1.0Creep up deviation related to nominal torque ofHBM loader at 200 N·m0 30 60 90 120 150 180 210 240 270 300 330 360 390 42018th18thTime in secondFigure A2-10. Creep deviation from inappropriate loader power transmission.All laboratories should check their own loader and avoid these unexpectedbehaviors. Usually, the creep behavior will effect to the repeatability of measurementsystem if there is variation in each applied torque dwell time and reading the results. Thedegree of effect depends on period of dwell time and filtering configuration. Theconclusion is shown in table A2-1.Table A2-1. Numerical value of creep effect of the loaderManufacture of Sensitivity coefficient creep loader express in %/secondloader 5 sec. 10 sec. 30 sec. 60 sec. 90 sec.CDI INC. 0.027 0.014 0.005 0.002 0.002AKO. 0.017 0.009 0.003 0.002 0.001NORBAR 0.020 0.010 0.004 0.002 0.001TOHNICHI 0.017 0.009 0.003 0.002 0.001HBM 0.016 0.008 0.003 0.001 0.001Modify by Lab.2 nd 0.026 0.013 0.005 0.002 0.002Modify by Lab.4 th 0.018 0.009 0.003 0.002 0.001Modify by Lab.6 th 0.031 0.016 0.006 0.003 0.002Modify by Lab.7 th 0.017 0.009 0.003 0.002 0.001Modify by Lab.13 th 0.033 0.017 0.006 0.003 .0002NIMT prefer to use 90 second to be an applied torque dwell time, so that it caneliminate creep effect of loader. The ± 3 second is a common uncertainty of appliedtorque dwell time that includes taking data for recording (Probably it is reduced to ± 1second in case of digital transferred data or automatically loading) and the uncertaintydue to creep effect should be 3 second times sensitivity that was declared in table A2-1. Itis possible to calibrate hand torque tools with applied torque dwell time at 5 second. Onthe other hand, it is not appropriate for torque wrench calibrator especially one withaccuracy equal or better than 0.25 %.43