UNCERTAINTY EVALUATION OF THE 20 kN·m DEADWEIGHT TORQUE STANDARD MACHINE

Koji Ohgushi, Takashi Ota, Kazunaga Ueda
Abstract:
A deadweight-type torque standard machine of 20 kN·m rated capacity (20 kN·m-DWTSM) has been designed and developed by the National Metrology Institute of Japan (NMIJ) at the National Institute of Advanced Industrial Science and Technology (AIST). Each uncertainty contribution comes mainly from the performance of each mechanical part of the 20 kN·m-DWTSM. Authors evaluated the uncertainty of the mass of the linkage weights, local acceleration of gravity, influence of air buoyancy on deadweight loading, initial moment-arm length (including CMM measurement and temperature compensation), and sensitivity of the fulcrum. This report deals especially with evaluation of the remaining contributions, namely the influence of arm flexure and reference line variation at the end of the moment-arm on best measurement capability (BMC). Estimation of BMC in the 20 kN·m-DWTSM gave a relative expanded uncertainty of less than 7.0 × 10-5 (k = 2) for the calibration range from 200 N·m to 20 kN·m.
Download:
IMEKO-TC3-2005-045u.pdf
DOI:
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Event details
IMEKO TC:
TC3
Event name:
Force, Mass and Torque Measurements
Title:
Theory and Applications in Laboratories and Industry
Place:
Cairo, EGYPT
Time:
19 February 2005 - 23 February 2005