A Travelling Reference Measuring System (TRMS) will circulate among the participants and they will compare the high AC voltages measured by their own measuring system with those obtained by the TRMS. Peak voltage and RMS values will be measured.
Determination of the measurement error of the TRMS should be made at the following voltage levels: 1 kV (or 750V), 40 kV, 80 kV, 120 kV, 160 kV and 200 kV.
Final Report 2016-10-31
The comparison has been completed and results are available in the KCDB.
A Travelling Reference Measuring System (TRMS) has been measured in peak and rms voltage values, in order to determine its measurement error at the voltage levels of 1 kV (or 750V), 40 kV, 80 kV, 120 kV, 160 kV and 200 kV.
The TRMS consisted of a capacitive divider with fixed input and grounding leads, a coaxial cable, a digital multimeter and a computer with a printer. The TRMS had two ranges, 20 kV and 200 kV, depending on the low voltage arm connected to the high voltage capacitor. Besides, an arbitrary waveform generator was included among the travelling devices to carry out the low voltage measurements of this comparison.
The parameters to measure were the scale factor of the TRMS, for both peak voltage and rms values, for voltages between 750 V and 200 kV.
The coordinating laboratory was LCOE (Spain) and the participating Institutes were LNE (France), VTT MIKES (Finland), RISE (Sweden), TÜBITAK UME (Turkey), PTB (Germany), BIM (Bulgaria), INRiM (Italy), VSL (Netherlands), VNIMS (Russia) and LCOE (Spain).
Results of the comparison proved the calibration and measurement capabilities of the participants in the field of high voltage AC measurement, specially when performing peak hv measurements up to 200 kV with expanded uncertainties in the range of 40 mV/V to 80 mV/V. The discrepancy between PTB and VTT (the two labs claiming the lowest uncertainties) results was on some measurements significantly larger than the respective uncertainties. PTB redesigned their measuring system and a subsequent bilateral comparison arranged with VTT solved the discrepancy.
Undertaking the work collaboratively through EURAMET has proved to be an excellent tool to compare calibration and measurement capabilities of NMI and DI, as well as an opportunity for several Institutes to improve their CMC´s.