Unilateral Degrees Of Equivalence Research Articles

Calibration of reference solar cells at standard test conditions

Main textThe EURAMET.PR-S5 intercomparison of the short circuit current of reference solar cells at standard test conditions was carried out as star type comparison. In total 6 participants with seven facilities took part, 1 from Europe (PTB/Germany with two facilities: the established DSR facility as pilot lab and the new Laser-DSR facility as participant) and 5 outside Europe (NIM/China, VNIIOFI/Russia, KRISS/South Korea, A-STAR/Singapore, ITRI/Chinese Taipei). Therefore, this comparison can be considered as a worldwide one as all NMIs world-wide that had built up facilities for the primary ISTC-calibration of reference solar cells when the measurements started, participated.For the calculation of the reference value of the supplementary comparison no participant had to be excluded and the used weighted mean with cut-off has been supported by all participants.The unilateral Degrees of Equivalence (DoE) calculated for each participant are fully 100 % consistent with their standard uncertainties. The largest En-value is 0.61 and therefore significant smaller than 1. The chi-square test is fully satisfied with 2.09 < χ2(5) = 11.07. Thus, the DSR method is highly suitable for the calibration of reference solar cells according to the short circuit current at standard test conditions.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 CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bayesian hypothesis testing for key comparisons

Unilateral degrees of equivalence are the key result in the analysis of key comparison data and they are used to approve, or disapprove, calibration and measurement capabilities of the participating laboratories. To this end, it is checked whether a degree of equivalence differs significantly from zero. Proceeding in such a way can be viewed as carrying out a classical hypothesis test. We develop a Bayesian counterpart to this approach which has the advantage that it can include prior assessment of the corresponding Consultative Committee about the calibration and measurement capabilities of the participating laboratories. Simple expressions are derived and their implementation is provided in terms of MATLAB® and R programs. The novel procedure is illustrated by its application to two recent key comparisons CCL-K1 and CCM.FF-K4.1.2011.

Final report on the key comparison CCPR-K5: Spectral diffuse reflectance

The CCPR K5 key comparison on spectral diffuse reflectance was carried out in the framework of the CIPM Mutual Recognition Arrangement, by 13 national metrology institutes (MMIs) as participants. The participants were CSIR-NML (South Africa), HUT (Finland), IFA-CSIC (Spain), KRISS (Republic of Korea), MSL (New Zealand), NIM (China), NIST (United States of America), NMIJ (Japan), NPL (United Kingdom), NRC (Canada), OMH (Hungary), PTB (Germany) and VNIIOFI (Russia Federation). NIST (USA) piloted the comparison.The aim of this comparison was to check the agreement of measurement of the spectral diffuse reflectance among participants, using the measurement geometry of d/0 or 0/d in the wavelength range of 360 nm to 820 nm at 20 nm increment. The comparison was a star type comparison with the samples provided by the pilot laboratory and with the measurement sequence: Pilot–Participant–Pilot. Spectralon and matte white ceramic tiles were used as the transfer standards. Each participant received three of each type of sample and at least one sample of each type was measured three times on three separate days, and the other two samples were measured once.The report presents the description of the measurement facilities, procedures and uncertainties of all the participants as well as the results of the comparison. Measurement results from the participants and their associated uncertainties were analyzed in accordance with the Guidelines for CCPR Key Comparison Report Preparation, using weighted mean with cut-off. For the calculation of the Key Comparison Reference Value (KCRV), as agreed by the participants, the data of both samples were used for the 460 nm to 820 nm region and only the data of the Spectralon samples were used in the spectral region of 360 nm to 440 nm. The unilateral degrees of equivalence (DoE) calculated for each participant are mostly consistent within the uncertainty (k = 2) of the DoE. This international comparison of spectral diffuse reflectance shows overall good agreement among all participants.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 CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report of international comparison on total luminous flux of LEDs: APMP.PR-S3b

We report the results of the international comparison of LED measurements on the quantity of total luminous flux. The comparison is conducted by circulating four different types of artefact LEDs (red, green, blue and white) to 13 National Metrology Institutes (NMIs). The artefact LEDs are prepared by functional seasoning to enable a temperature correction based on the junction voltage measurement. The comparison reference values and the unilateral degrees of equivalence (DoEs) of each participant are calculated for each type of LEDs from the reported measurement results.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 APMP, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report of international comparison on averaged LED intensity: APMP.PR-S3a

We report the results of the international comparison of LED measurements on the quantity of averaged LED intensity in condition B defined by the International Commission on Illumination (CIE). The comparison is conducted by circulating five different types of artefact LEDs (red, green, blue, white and diffuser-type green) to 15 National Metrology Institutes (NMIs). The artefact LEDs are prepared by functional seasoning to enable a temperature correction based on the junction voltage measurement. The comparison reference values and the unilateral degrees of equivalence (DoEs) of each participant are calculated for each type of LEDs from the reported measurement results.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 APMP, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Final report of international comparison on emitted colour of LEDs: APMP.PR-S3c

We report the results of the international comparison of LED measurements on the quantity of chromaticity coordinate CIE 1931 (x, y). The comparison is conducted by circulating five different types of artefact LEDs (red, green, blue, white and diffuser-type green) to 14 National Metrology Institutes (NMIs). The artefact LEDs are prepared by functional seasoning to enable a temperature correction based on the junction voltage measurement. The comparison reference values and the unilateral degrees of equivalence (DoEs) of each participant are calculated for each type of LEDs from the reported measurement results.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 APMP, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Linking of a RMO key comparison to a related CIPM key comparison using the degrees of equivalence of the linking laboratories

A procedure is proposed for linking the results of a RMO key comparison to those of a related CIPM key comparison when different travelling standards are used. The approach is based on a relationship between unilateral and bilateral degrees of equivalence (DOEs) as defined in the MRA, and it assumes that the quantities being estimated by the unilateral DOEs for the linking laboratories are the same in the CIPM and the RMO key comparisons.We show that in the particular situation of single stable travelling standards in the two key comparisons the assumptions and the results of the approach are in line with previously proposed linking procedures which employ an additive shift to the RMO data prior to their comparison with the CIPM key comparison reference value. However, the procedure put forward here yields (slightly) smaller linking uncertainties compared with these methods and, more important, it is generally applicable also in situations when several travelling standards are used or when the travelling standard shows a drift.

Final report on EUROMET comparison EUROMET.PR-S2 (Project No. 156): Responsivity of detectors for radiant power of lasers

The EUROMET.PR-S2 intercomparison of Radiant Power of High Power Lasers for five measurands was carried as a combined round-robin/star type comparison. In total nine participants took part, five from Europe (national metrology institutes of France, Germany (pilot), Great Britain, Romania, Sweden) and four outside Europe (national metrology institutes of Australia, Japan, South Africa and The United States of America). Therefore, this comparison can be considered as a worldwide one. The measurements took place from January 2005 to September 2007.All participants supplied detailed reports of their measurements including full uncertainty statements. All measurement results reported by the participants were used for the intercomparison and no measurement was subject to rejection. The analysis method introduced in section 6 follows the Guidelines for CCPR Comparison Report Preparation and has been accepted by all participants.For the calculation of the supplementary key comparison reference value no participant had to be excluded and the weighted mean with cut-off used here has been supported by all participants.The unilateral degrees of equivalence (DoE) calculated for each participant are approximately 63% consistent with their uncertainties at the k = 2 level and approximately 81% consistent within k = 3.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 (MRA).

Final report on the CIPM key comparison CCPR-K1.b: Spectral irradiance 200 nm to 350 nm

The CCPR K1.b key comparison of spectral irradiance from 200 nm to 350 nm was carried out to meet the requirements of the Mutual Recognition Arrangement by five participating national metrology institutes (NMIs). The comparison was arranged as a star comparison with deuterium lamp systems (DLS) as transfer standard. PTB (Germany) piloted the comparison and, by measuring all lamps, provided a link between participants' measurements. The participants were BNM–INM (France), NIST (United States of America), NPL (United Kingdom), NRC (Canada) and PTB (Germany).The use of multiple lamps and multiple measurements ensured sufficient redundancy that all participants were adequately represented. All participants supplied detailed reports of their measurements including full uncertainty statements. All measurement results reported by the participants could be used for the intercomparison and no measurement was subject to rejection.The comparison data were analyzed following the Guidelines for CCPR Comparison Report Preparation. A minor adaptation of the proposed analysis method allowed a clear separation between the pilot PTB and the participant PTB. This led to a Key Comparison Reference Value (KCRV) that does not require an absolute unit realization by the pilot.Across the spectral region (200 nm to 350 nm) there were 16 wavelengths at which a comparison was made. These wavelengths in 10 nm steps were treated entirely independently and thus the report describes 16 comparisons. For the calculation of the key comparison reference values no participant had to be excluded and the weighted mean with cut-off has been supported by all participants. The unilateral degrees of equivalence (DoE) calculated for each participant are 96% consistent with their uncertainties at the k = 2 level and fully consistent within k = 3.These results impressively demonstrate the substantial improvements in UV radiometry during recent years and the excellent calibration capabilities of all participants. The outstanding quality of the results was greatly supported by the availability of high quality transfer standards. For the first time the stability and reproducibility of the DLS allowed a reasonable direct comparison of UV spectral irradiance calibrations.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 CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Final report on CCPR K1-a: Spectral irradiance from 250 nm to 2500 nm

The CCPR K1-a key comparison of spectral irradiance (from 250 nm to 2500 nm) was carried out to meet the requirements of the Mutual Recognition Arrangement by 13 participating national metrology institutes (NMIs). Because of the fragile nature of the tungsten halogen lamps used as comparison artefacts, the comparison was arranged as a star comparison with three lamps per participant. NPL (United Kingdom) piloted the comparison and, by measuring all lamps, provided a link between participants' measurements. The other participants were BNM–INM (France), CENAM (Mexico), CSIRO (Australia), HUT (Finland), IFA–CSIC (Spain), MSL–IRL (New Zealand), NIM (China), NIST (United States of America), NMIJ (Japan), NRC (Canada), PTB (Germany) and VNIIOFI (Russian Federation).Before the analysis was completed and the results known, the pilot discussed with each participant which lamp measurements should be included as representative of their comparison. As a consequence of this check, at least one measurement was excluded from one third of the lamps because of changes due to transportations. The comparison thus highlighted the difficulty regarding the availability of suitable transfer standards for the dissemination of spectral irradiance. The use of multiple lamps and multiple measurements ensured sufficient redundancy that all participants were adequately represented. In addition, during this pre-draft A phase all participants had the opportunity to review the uncertainty budgets and methods of all other participants. This new process helped to ensure that all submitted results and their associated uncertainties were evaluated in a consistent manner.The comparison was analysed using a model-based method which regarded each lamp as having a stable spectral irradiance and the measurements made by an NMI as systematically influenced by a factor that applies to all that NMI's measurements. The aim of the analysis was to estimate the systematic factor for each NMI.Across the spectral region (250 nm to 2500 nm) there were 44 wavelengths at which a comparison was made. These were treated entirely independently and thus the report describes 44 comparisons. For wavelengths from 250 nm to 800 nm (apart from 300 nm) all participants had unilateral degrees of equivalence (DoEs) with values consistent with their uncertainties for a coverage level k = 2. At all other wavelengths (apart from 1400 nm) all participants achieved consistency at the k = 4 level for the unilateral DoEs and the vast majority within k = 3.The results are a significant improvement over those of the previous comparison in 1990, especially considering that the declared uncertainties of most participants have been substantially improved over the intervening decade. These results are evidence of the value of the effort devoted to the development of improved spectral scales (and of the evaluation of their uncertainty) by many NMIs in recent years.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 CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).