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1. Sizes to be measured
The unit of electric current is the ampere, symbol A, one of the seven basic quantities of the international system of units. The current definition of the ampere is based on a fixed numerical value of the elementary charge, e, equal to 1.602 176 634 x 10 –19 when expressed in C (coulomb), a unit equal to A.s (ampere.second). This definition was adopted in November 2018 at the 26th meeting of the General Conference on Weights and Measures (CGPM), in Versailles.
The variation of an electric current can be continuous, alternating or pulsed.
Direct current is defined as a current whose value remains constant over time, or whose variations are negligible during the measurement period. In this case, a single parameter is sufficient to characterize it: its mean value....
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Sizes to be measured
Measurement methods and instruments
Bibliography
- (1) - DC GRIDS - Réseaux CC 20NRM03. - (2023). Disponible en ligne https://dc-grids.nl/
- (2) - IEC JWG 9 LVDC distribution. - Disponible en ligne
Standards and norms
- Instrument transformers – Part 1: General requirements. - NF EN 61869-1 - Décembre 2009
- Instrument transformers – Part 2: Additional requirements for current transformers. - NF EN 61869-2 - Mai 2013
- High-intensity testing techniques – Definitions and requirements for test currents and measuring systems. - NF EN 62475 - Mars 2011
Websites
BIPM – The International System of Units – 9th edition. Appendix 2 – Practical realization of the main units
https://www.bipm.org/fr/publications/si-brochure
COFRAC – French Accreditation Committee
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