High accuracy AC current sources calibration by single junction thermal converters at INM

• Published in: Dyna (Medellín, Colombia) Colombia), 2021-01, Vol.88 (216), p.117-125
• Main Authors: Hernández Prada, Carlos Fernando, Avellaneda, Mauricio Sáchica, Alexander Martínez lópez
• Format: Article
• Language: English
• Subjects: AC-DC Current Transfer Standard; Accuracy; Alternating current; alternating current (AC); calibración; Calibration; Converters; convertidor térmico de corriente; convertidor térmico de unión simple; Current sources; DC current transfer standard; intensidad de corriente alterna (CA); International System of Units; Metrology; patrón de transferencia AC; Single Junction Thermal Converter; Temperature effects; Thermal Current Converter; traceability; Transconductance; trazabilidad; Uncertainty
• ISSN: 0012-7353; 2346-2183
• DOI: 10.15446/dyna.v88n216.86244

The National Metrology Institute of Colombia (INM) uses high accuracy calibrators (such as Fluke 5720A/5730A) as AC current reference standards. We describe the implementation at INM of AC-DC current transfer standards by single junction thermal converters (SJTC) to improve the accuracy of AC measurements and give traceability to the International System of Units (SI) within the country. We describe the measurement model, present the uncertainty budget estimation accordingly to the Guide to the Expression of Uncertainty in Measurement (GUM) and analyze the effect of temperature and electrostatic on measurements. Expanded uncertainties between 68 μA/A and 2.6 mA/A were obtained for the calibration of high accuracy calibrators and transconductance amplifiers for currents from 5 mA to 20 A (40 Hz to 5 kHz). The obtained measurement results are compatible with calibration results from the National Metrology Institutes like Centro Nacional de Metrología from Mexico (CENAM) and Accredited International Laboratories like Fluke.