Comparison Of Resistance Standards Research Articles

Final report on bilateral comparison SIM.EM-S9.b: Comparison of resistance standards at 1 Ω and 10 kΩ between INIMET (Cuba) and INTI (Argentina), March to October 2012

The CIPM MRA states that its technical basis is a set of results obtained in a course of time through key comparisons carried out by the Consultative Committees of the CIPM, the BIPM and the Regional Metrology Organizations (RMOs). As part of this process, INTI (Argentina) has participated in several key and supplementary comparisons. By means of procedures for linking key comparison data, a bilateral comparison would help to provide assurance of equality in measurements between the participating laboratories. With this end, the comparison SIM.EM-S9.b of 1 ohm and 10 kiloohm standard resistors of INIMET (Cuba) and INTI was carried out from March to October 2012.The obtained results were very good. They show that the resistance standards maintained by INTI and INIMET were equivalent, within their combined uncertainties, on the mean date of the comparison.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

RMO key comparison EURAMET.EM-K2.1: Comparison of resistance standards at 10 MΩ and 1 GΩ

Four National Metrology Institutes, among them three EURAMET members, participated in the follow-up comparison EURAMET.EM-K2.1. The comparison aimed at evaluating the degrees of equivalence of the measurements of 10 MΩ and 1 GΩ resistance standards. Through the pilot laboratory, the results are linked to comparisons EUROMET.EM-K2 and CCEM-K2 respectively. At 1 GΩ, all results supplied by the participants agreed with the comparison reference value within the expanded uncertainty. At 10 MΩ, a slight disagreement with the KCRV for three of the four participants was observed.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report on supplementary comparison EURAMET.EM-S32: Comparison of resistance standards at 1 TΩ and 100 TΩ

Resistance standards with values in the TΩ range play an important role in electrical instrumentation. The calibration of such standards is, thus, a service offered by many metrology institutes. The techniques used to measure very high resistance values differ quite substantially from the calibration techniques applied in the lower resistance ranges. For this reason, the EURAMET technical committee for electricity and magnetism decided in 2008 to organise for the first time a supplementary comparison of resistance at 1 TΩ and 100 TΩ based on well characterized travelling standards.Eighteen European National Metrology Institutes participated in the comparison. With some exceptions, the results supplied by the participants agree reasonably well with the comparison reference value within the expanded uncertainty.As observed in other resistance comparisons, the characteristics of the standards used as transport artefacts ultimately limit the accuracy of comparisons in this field. The transport behaviour is difficult to model and introduces an undesired bias in the laboratory results. The transport uncertainties are at the level of the uncertainties claimed by some of the participants and, thus, limit the meaningfulness of the comparison results.Another remarkable observation is the big difference in the uncertainty statements made by the participants, even in cases where similar measurement systems were used. The results of the comparison allow the participants to critically review their measurement procedures and uncertainty models.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Evaluation of Two Alternative Methods to Calibrate Ultrahigh Value Resistors at INRIM

In the framework of the preparation of the National Institute of Metrological Research (INRIM) to its participation at the “Supplementary Comparison EURAMET.EM-S32 Comparison of Resistance Standards at 1 TΩ and 100 TΩ,” an evaluation of two measurement techniques for high resistance measurements at INRIM has been made. The first method, working between 10 MΩ and 1 TΩ, is based on a digital multimeter and on a dc voltage (dcv) calibrator, the second, working up to 100 TΩ, is based on a modified Wheatstone bridge with two programmable dcv calibrators in two arms of the bridge and a programmable electrometer as null detector. A description of both methods, a detailed uncertainties budget at 1 TΩ at 1000 V level according to the ISO Guide to the Expression of Uncertainty in Measurements, and the comparison of the results at 100 GΩ and at 1 TΩ are reported.

Final report on RMO key comparison EUROMET.EM-K2: Comparison of resistance standards at 10 MΩ and 1 GΩ

Twenty-four national metrology institutes, among them 22 EURAMET members, participated in the comparison EUROMET.EM-K2 aimed at evaluating the degrees of equivalence of the measurements of 10 MΩ and 1 GΩ resistance standards. The link to the CCEM comparison CCEM-K2 and the degrees of equivalence with respect to the key comparison reference value were also evaluated. With three exceptions at 10 MΩ, all results supplied by the participants agreed with the comparison reference value within the expanded uncertainty.The method of constrained least squares was applied to calculate the comparison reference value. This method has proven to be useful in this analysis, because it provides a single, consistent and transparent approach for the determination of the key values of this measurement comparison involving multiple artefacts and overlapping loops.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Comparison of resistance standards between the National Institute of Metrology (China) and the Electrotechnical Laboratory (Japan)

The resistance standard maintained at the Electrotechnical Laboratory (ETL, Japan) is based on the resistance of the second plateau of the quantized Hall resistance, RH(2). A resistance ratio bridge with a cryogenic current comparator (CCC) is used for the measurements. The typical relative standard uncertainty in measuring a 1 Ω resistor is estimated to be about 4 × 10-9. The resistance standard maintained at the National Institute of Metrology (NIM, China) is based on the average value of six wire-wound 1 Ω resistors. It was monitored using the ETL quantum Hall effect (QHE) resistance standard in 1992, 1996 and 2000 by bringing 1 Ω resistors from the NIM to the ETL or from the ETL to the NIM. The drift rate of the standard was measured to be -0.024 µΩ/year. The NIM has developed a CCC bridge. The typical relative standard uncertainty in measuring a 1 Ω resistor using this CCC bridge and the QHE system of the NIM is estimated to be about 7 × 10-9. The NIM QHE system was compared with the ETL QHE resistance standard by bringing three 1 Ω resistors from the ETL to the NIM. Differences in the measurements were (+3.9 ± 8.9) nΩ, (+1.0 ± 9.9) nΩ and (-0.9 ± 9.1) nΩ, respectively.