EVALUATION OF ACTUAL SENSITIVITY LIMIT IN A 10 N·m DEAD WEIGHT TORQUE STANDARD MACHINE AND STABILITY OF A NEW 1 N·m TORQUE TRANSDUCER
Atsuhiro Nishino, Koji Ogushi, Kazunaga Ueda
Abstract:
A 10 N·m dead weight torque standard machine (10-N·m-DWTSM) has been under development at NMIJ/AIST since 2006 to expand the range of the torque standard. Estimation of the sensitivity limit of the fulcrum is one of the most important issues to realize a precise reference torque of small capacity by using a dead weight torque standard machine. In this study, a torque transducer was installed on the 10-N·m-DWTSM in order to keep the moment-arm on the horizontal line (balancing). The sensitivity limit of the fulcrum under real calibration conditions was estimated by reading the change in the output from the torque measuring device (TMD: the torque transducer with a cable and an indicating device) when small weights were loaded or unloaded. The small weights used in the experiment were 0.5 mg, 1 mg, 10 mg, and 100 mg. Equivalent radial loads from 0.1 N·m to 10 N·m were imposed on the fulcrum during the sensitivity measurement. As a result, the sensitivity limit of the fulcrum was confirmed to be sufficient to load at least 0.5 mg. A relative sensitivity limit of the fulcrum of less than 2.5 × 10-5 and relative reproducibility of the sensitivity limit of the fulcrum of less than 1.7 × 10-6 could be obtained within the calibration range from 0.1 N·m to 10 N·m.
It is also important to develop small-rated-capacity torque transducers that can be used as a transfer standard. Therefore, a transducer with a rated capacity of 1 N·m was developed in parallel with the development of the 10-N·m-DWTSM. The stability of the 1 N·m TMD has been evaluated over a period of one year.
Keywords:
torque standard, uncertainty, sensitivity
Download:
IMEKO-TC3-2010-025.pdf
DOI:
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Event details
IMEKO TC:
TC3
Event name:
TC3 Conference 2010
Title:

21st Conference on Measurement of Force, Mass and Torque (together with TC5 HARDMEKO 2010 and 2nd TC22 Meeting on Vibration Measurement)

Place:
Pattaya, THAILAND
Time:
21 November 2010 - 25 November 2010
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