M Helmy A Raouf， Rasha S M Ali
(Department of Electrical Quantities Metrology， National Institute for Standards (NIS), Giza 12211-136， Egypt)
Abstract： A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed relays. This new switch is introduced to establish a fully automated system for AC-DC measurements through AC-DC transfer standards for the first time at the National Institute for standards (NIS) in Egypt. The implemented circuit of the automatic AC-DC switch and its protection are presented in details. An AC voltage source is calibrated against DC voltage source by using the demonstrated automatic switch as an application. The calibrated voltage ranges are 2 V, 6 V, 20 V and 60 V as examples. The uncertainty budget is also evaluated for the calibrated values.
Key words： AC voltage measurement; AC-DC transfer standard; automatic switching system; uncertainty
CLD number： TM93 Document code： A
Article ID： 1674-8042（2017）01-0027-05doi： 10.3969/j.issn.1674-8042-2017-01-005
References
［1］Flueli M, Fasel W. A fast switching system for AC-DC transfer measurements. In: Proceedings of Conference on Precision Eletromagnetic Measurement, 1998: 27-28.
［2］Ali R S M. The effect of changing the applied sequence using the TVC on the accuracy of the AC signal calibration. Sensors and Transducers, 2013, 153(6): 155-160.
［3］Pogliano U, Bosco G C, Lanzillotti M. Generalized automatic system for AC/DC transfer, AC voltage, and AC current measurements, IEEE Transaction on Instrumentation and Measurement, 2006, 55(5): 1747-1751.
［4］Liu L X, Chua S W, Chen T P, et al. Improvements in the PSB AC-DC transfer capabilities and a proposal for range extension. In: Proceedings of Conference on Precision Eletromagnetic Measurement 2000: 379-380.
［5］Pogliano U, Trinchera B. RMS voltage measuring system for precise evaluation of electric quantities. Metrology and Measurement Systems Journal, 2007, 14(4): 555-562.
［6］Atmel. ATmega8A complete datasheet. 2015-09-01［2016-12-21］. http:∥www.waveshare.net/datasheet/ATMEL_PDF/ATmega8.PDF.
［7］MEDER Electronic. BE05-2A85-P be reed relay datasheet.2015-01-27［2016-12-21］. https:∥standexelectronics.com/wp-content/uploads/datasheet_reed_relay_BE.pdf.
［8］Pal B, Ahmad S, Govil A K, et al. Automation and evaluation of two different techniques to calibrate precision calibrators for low frequency voltage using thermal devices. Precision Electromagnetic Measurement, 2010, 28(28): 171-172.
［9］Ali R S M. Comparison between two different designs in the AC voltage measurement. Measurement, 2011, 44(9): 1539-1542.
［10］Joint Committee for Guides in Metrology. Evaluation of measurement data-Guide to the expression of uncertainty in measurement. 2008-09-01［2016-12-21］. http:∥www.bipm.org/utils/common/documents/jcgm/JCGM_100_2008_E.pdf.
AC-DC全自动测量系统中自动开关的研制
M Helmy A Raouf， Rasha S M Ali
（国家标准化研究所 电量计量部，吉萨 12211-136， 埃及）
摘要:采用了三个双刀单掷簧片继电器研制了一个快速自动A-DC转换开关。 依据A-DC转化标准， 所研制的开关首次用于埃及国家标准化所的AD-DC全自动测量系统中。 对自动AC-DC转换开关的电路及保护电路进行了介绍， 并使用该转换开关实现了从AC电压源到DC电压源转换的标定， 标定的DC电压源量程为2、 6、 20和 60 V。 最后， 对校准值的不确定性进行了估算。
关键词:交流电压测量； AC-DC转换标准； 自动转换系统； 不确定性
引用格式：Raouf M H A， Ali R S M. Fabrication of automatic switch for AC-DC completely automated measurement system at NIS. Journal of Measurement Science and Instrumentation, 2017, 8(1)： 27-31. ［doi： 10.3969／j.issn.1674-8042.2017-01-005］
[full text view]
