Rasha S.M.Ali, M.Helmy A.Raouf
(Dept. of Electrical Quantities Metrology, National Institute of Standards, Giza 136, Egypt)
Abstract-An automated multi-range multipliers (range resistors) system is established for the AC voltage measurements by using a thermal voltage converter. It is performed automatically by selecting the appropriate multiplier whose voltage range contains the voltage to be measured without changing it manually through a new designed system. It consists of control part through a micro-controller controlled by specified prepared Lab-VIEW program and switching part through electronic relays in one circuit as clearly described in this work. It is used for measuring the ac voltage in the range from 1 V to 200 V. Also, it can be used for the voltage ranges up to 1 000 V by putting some factors into consideration. The AC-DC transfer differences for these multipliers combined with thermal voltage converter are determined automatically against another standard thermal voltage converter by using another Lab-VIEW program.
Key words-AC voltage measurement; thermal voltage converter; AC-DC transfer standard; multipliers; uncertainty
Manuscript Number: 1674-8042(2011)03-0297-03
doi: 10.3969/j.issn.1674-8042.2011.03.022
References
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[2] The National Physical Laboratory (NPL) Website. http://www.npl.co.uk/electromagnetic/delf/actransfer.html
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[4] 1398B Series Thermal Voltage Converters. operation manual, Ballantine Laboratories, Inc., 2000.
[5] K. J. Lentner, Donald R. Flach, 1983. An automatic system for AC-DC calibration. IEEE Trans. on Instrumentation and Measurement, IM-32(1): 51-56.
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