Proficiency test for gamma-emitting radionuclides in seawater: A case study from South Korea.

The Asia Pacific Metrology Program (APMP) and the Asia Pacific Laboratory Accreditation Cooperation (APLAC) joint Proficiency Testing (PT) programs for toxic elements such as cadmium (Cd) and lead (Pb) or nutritional elements such as iron (Fe) and zinc (Zn) in food were organized by the Korea Research Institute of Standards and Science (KRISS) with the aim of enhancing the quality of measurement and metrological traceability in various economies of the Asia Pacific region by evaluating the performance with rigorous evaluation. Three APMP-APLAC joint PT programs for elemental analyses were carried out by KRISS sequentially, where candidate certified reference materials (CRMs) were used as the PT materials and metrologically traceable certified reference values (RVs) were used as the PT assigned values for the evaluation of participants' results, which allows reliable evaluation of participant performance. This article describes the operation of the PTs and the overall performance of the participating laboratories. The effectiveness of these joint PT programs and trends in PT performance assessment are also discussed. These PT programs confirm the significant importance of using the metrologically traceable RVs instead of the consensus values from participants as the PT assigned value for reliable assessment. The lack of understanding of the concept of coverage factor, degree of freedom, standard uncertainty, and expanded uncertainty was revealed by some participants in these PT programs. Interpreting the zeta-scores or En scores, which are derived by using measurement uncertainties, in conjunction with the z-scores is highly meaningful for assessing participants' ability in measurement capabilities and measurement uncertainty evaluation. Assessment of participants' performance considering measurement uncertainties helps the participants to check how reasonable their measurement uncertainty estimation was. The results of PTs also demonstrated that these PT programs are useful for improving the measurement capability of the laboratories, whereas more capability-building in uncertainty evaluation is required for further improvement.

As a part of the ongoing BIPM key comparisons BIPM.EM-K11.a and b, a comparison of the 1.018 V and the 10 V voltage reference standards of the BIPM and the Korea Research Institute of Standards and Science (KRISS), Daejeon, Republic of Korea, was carried out in February 2008. One KRISS Zener diode (Fluke 732A) was used as a transfer standard. KRISS measurements were carried out by comparison with the KRISS primary voltage standard consisting of a Josephson Voltage Standard. BIPM measurements were carried out on site, at KRISS by comparison with the BIPM transportable Josephson Voltage Standard. The transfer standard wasn't characterized for the effects of temporal drift and environmental influences as both participants measured the Zener within a short time period. For day to day measurement, the voltage assigned by the BIPM to the transfer standard, UBIPM, was computed using a linear least-square fit to all of the data from the BIPM and referenced to the mean time of the KRISS measurements. The final result is the simple mean of the daily result over the total period of the comparison (6 days).The final result of the comparison is presented as the difference between the value assigned to a 1.018 V and 10 V standard by the KRISS, UKRISS, and that assigned by the BIPM, at the KRISS, UBIPM, which for the reference date is:at 1.018 V, UKRISS − UBIPM = 70 nV; uc = 48 nV on 2008/02/26 at 10 V, UKRISS − UBIPM = −31 nV; uc = 100 nV on 2008/02/26,where uc is the standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM, the uncertainty of the representation of the volt at KRISS, both based on KJ-90, and the uncertainty related to the comparison.This satisfactory result shows that the voltage standards maintained by the KRISS and the BIPM were equivalent, within their stated expanded 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 the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Asia-Pacific Metrology Program (APMP) and Asia-Pacific Laboratory Accreditation Cooperation (APLAC) joint proficiency testing with metrological reference values for hazardous elements in cabbage

Vertical distribution of 129I released from the Fukushima Daiichi Nuclear Power Plant in the Kuroshio and Oyashio current areas

As a part of the ongoing BIPM key comparisons BIPM.EM-K10.b, an on-site, direct comparison of the 10 V Josephson array voltage standard of the Bureau International des Poids et Mesures (BIPM) was made with that of the Korea Research Institute of Standards and Science (KRISS), Republic of Korea, in February 2008.The final result of the comparison is presented as the difference between the value assigned to the transportable 10 V BIPM Josephson Voltage Standard by the KRISS, at the KRISS, to the theoretical value assigned to the BIPM Josephson Voltage Standard: (UKRISS − UBIPM)/UBIPM = +1.7 × 10−10 and uc/UBIPM = 1.3 × 10−10 where uc is the relative combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM, the uncertainty of the representation of the volt at KRISS, both based on KJ-90, and the uncertainty related to the comparison.The results are in very good agreement and show that the primary voltage standards maintained by the KRISS and the BIPM were equivalent, within their stated expanded uncertainties.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).

Korea Research Institute of Standards and Science (KRISS) and All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI) conducted a bilateral comparison on spectral irradiance over the spectral region from 250 nm to 2500 nm in 2008. The aim of this comparison was to assess the equivalence of the spectral irradiance scales between the two laboratories and to link the KRISS spectral irradiance scale to the results of key comparison CCPR-K1.a carried out in the years 2000–2003. The technical protocol was approved by the CCPR Working Group on Key Comparisons in April 2008. KRISS acted as the pilot to reduce the workload of VNIIOFI as the link laboratory. PTB acted as the neutral partner to ensure blindness of the comparison results. PTB collected the measurement results from and sent them back to both participants. KRISS prepared this report based on the measurement results distributed by PTB. The spectral irradiances measured by KRISS and VNIIOFI agreed within the standard uncertainties (k = 1) from 250 nm to 2500 nm. The unilateral degrees of equivalence of KRISS were calculated using the unilateral degrees of equivalence of VNIIOFI to link the KRISS spectral irradiance scale to the key comparison CCPR-K1.a. The uncertainties of the unilateral degrees of equivalence of KRISS were determined using the uncertainties of KRISS and VNIIOFI measurements and the uncertainties of the unilateral degrees of equivalence of VNIIOFI, and taking into account the correlation of VNIIOFI measurements between the CCPR key and this bilateral 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 the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

There exist many interlaboratory comparisons (ILCs). Frequently, they are used to detect, study, and compensate for (un)known effects affecting a measurement result. Another frequent use of ILCs is to evaluate measurement capability. However, an ILC can only be used for one intended use at a time. For the purpose of this Column, we define a PT (Proficiency Testing) programme as an interlaboratory comparison study used for the sole and exclusive purpose of evaluating the measurement capability (proficiency) of one or more participating laboratories. In a previous Column [1], the declaration by participating laboratories of their measurement results (defined in VIM entry 2.9 [2]) in a Proficiency Testing (PT) programme was discussed. For a definition of measurement capability, see entry 7.3-1 in the IUPAC study referred to in [3]. The usefulness of comparative graphs as easy means to evaluate this measurement capability was stressed. However, a measurement result must comprise its measurement uncertainty in order to be a valid result (see definition in VIM entry 2.9). Sadly enough, that is not done in many cases. Only the measured values are given and compared. Measurement results which do not contain a statement of measurement uncertainty ‘‘cannot be compared’’, as explicitly stated in section 0.1 in [4], yet being ‘‘comparable’’ is ‘‘a worldwide need’’ for measurement results as specified in section 0.3 in [4]. In addition, the metrological traceability (defined in VIM entry 2.41 in [2]) of a result must be indicated. An absence of these two characteristics casts a twofold doubt on such incomplete pictures and, therefore, onto the very validity of any conclusion of the programme. Measurement uncertainty and metrological traceability are intrinsic characteristics of any measurement result and hence also of any participant’s measurement result in a PT programme. They are conditions for the very metrological comparability of such results (defined in VIM entry 2.46 [2]). In addition, this metrological traceability must be established to the same reference (defined in VIM entry 2.41 NOTE 1 [2]). That logically leads to the question against which criterion this evaluation must be performed. A possible answer is: through the assignment to the programme by the organizer, of a ‘‘reference value’’ (short for ‘‘reference quantity value’’) with a clearly demonstrated metrological traceability. The definition of ‘‘reference value’’ is given in VIM entry 5.18 and its NOTE 2 [2]. Several reference values are possible (VIM entry 5.18 and its NOTE 2 in [2], as made available from:

Radioactive emissions into the environment from the Fukushima Daiichi Nuclear Power Plant accident led to global contamination. Radionuclides such as 131I, 134Cs, and 137Cs were further transported to North America and Europe. Thus, the Fukushima Daiichi Nuclear Power Plant accident is a global concern for both human health and the ecosystem because a number of countries ban or impose restrictions the import of Japanese products. In the present study, three-year (May 2011 to May 2014) fluctuations and accumulations of Cs, 134Cs, and 137Cs in two salmonid fish, white-spotted char and masu salmon were examined in Northeast Japan. The total Cs, 134Cs, and 137Cs levels in the fish gradually decreased throughout the three-year studied period after the Fukushima Daiichi Nuclear Power Plant accident; however, higher levels (more than 100 Bq kg-1) were still detected in the Fukushima prefecture and neighboring prefectures in Japan 3 years after the Fukushima Daiichi Nuclear Power Plant accident. Spatial radiocesium levels gradually decreased with increasing distance from the Fukushima Daiichi Nuclear Power Plant (Fukushima prefecture). The radiocesium levels facing the Pacific Ocean area were generally higher than those facing the Sea of Japan area. These results suggest that radionuclides from Fukushima Daiichi Nuclear Power Plant are still widely distributed and remain in the natural environment in Northeast Japan.

Bilateral comparison of the absorbed dose to water in high energy X-ray beams between the KRISS and the NMIJ

Bilateral comparison between viscosity measurement standard systems developed by KRISS and PTB

A comparison of antenna parameters (i.e. antenna gain, radiation pattern and reflection coefficient) for R-band (1.7–2.6 GHz) and S-band (2.6–3.95 GHz) standard gain antennas has been performed between Korea Research Institute of Standards and Science (KRISS) and seven domestic participants including private companies and public organizations. Its purpose, as a proficiency test program of the ‘Antenna Measurement Club’ of KRISS, was to check equivalences in antenna parameters measurements, particularly in R-/S-band, between KRISS and participants to support antenna manufacturers and end users in Korea. This comparison uses two traveling standards (i.e. R-/S-band pyramidal standard gain horn antennas) and measurement parameters are the power gain, radiation pattern and reflection coefficient of the traveling standards. Gain comparison method and extrapolation method are used in this comparison.

Background. According to the guidelines of the Department of Health (DOH)’s Health Facilities and Services Regulatory Bureau (HFSRB), accreditation of drug testing laboratories (DTLs) requires annual participation in a proficiency testing (PT) program. Since 2009, the National Reference Laboratory for Environmental and Occupational Health, Toxicology and Micronutrient Assay of the East Avenue Medical Center (NRL-EAMC) has conducted the PT program for DTLs. Objectives. This article aims to provide a general overview of the PT program conducted for screening drug testing laboratories (SDTLs) and to examine data on laboratories’ participation and performance in the PT program. Methodology. Laboratories registered for the PT program were given ten 3-mL synthetic urine specimens which may or may not contain drugs of abuse such as methamphetamine and tetrahydrocannabinol at or above the cut-off level. Laboratories analyzed the PT specimens using immunoassay test kits. The results of the analysis were reported back to NRL-EAMC. The performance of the laboratories in the PT depends on the number of incorrect responses. Results. For ten years (2009-2019), 1102 ± 188 laboratories annually participated in the program. The mean passing rate was 96.6 ± 4.8%. The number of laboratories which initially failed the PT program significantly decreased from 2009 (15.1%) to 2012 (1.5%). From 2013 to 2019, only below 2.5% of the participating laboratories initially failed the PT. On average, 48.4 ± 18.4% of the laboratories achieved an excellent performance, 34.0 ± 13.6% had a highly satisfactory performance, and 14.3 ± 5.4% got an acceptable performance. Conclusion. The continued decreasing number of laboratories which failed the PT signifies the improvement of laboratories in urine drug testing. In general, some laboratories participating in the PT for the first time are the ones which initially fail the PT which could be due to a lack of experience in handling PT test items. The PT program highlights the effectiveness of quality control procedures being implemented in a drug testing laboratory.

<p class="Abstract">An inter-laboratory comparison of the calibration capability for torque measuring devices (TMDs) was conducted between the National Metrology Institute of Japan (NMIJ) in the National Institute of Advanced Industrial Science and Technology (AIST) and the Korea Research Institute of Standards and Science (KRISS). Three high-performance torque transducers having rated capacities of 100 N·m, 1 kN·m, and 2 kN·m, and a bridge calibration unit (BN100A) were used as the transfer devices. The 1 kN·m and 2 kN·m transducers had one bridge, but the 100 N·m transducer had two bridges that acquired data more reliably. An identical indicator/amplifier type (DMP40) owned by each laboratory was used. All of the transducers and BN100A were transferred from NMIJ to KRISS. For the comparison, NMIJ used 1 kN·m and 20 kN·m deadweight torque standard machines (TSMs), and KRISS used a 2 kN·m deadweight TSM. In particular, the capability of the 1 kN·m TSM at NMIJ was examined after some improvements. In the calibration range from 50 N·m to 2 kN·m, relative deviations were less than 3.0 × 10<sup>-5</sup> for increasing torques. Sufficiently small deviations were obtained between the calibration results in the two laboratories, as compared with their calibration and measurement capabilities (CMCs), which were 3.5 × 10<sup>-5</sup> for the 1 kN·m TSM at NMIJ, 7.0 × 10<sup>-5</sup> for the 20 kN·m TSM at NMIJ, and 5.0 × 10<sup>-5</sup> for the 2 kN·m TSM at KRISS (as relative expanded uncertainties).</p><p class="Abstract"> </p>

Comparison of the standards for absorbed dose to water of the IAEA and the KRISS, Korea in accelerator photon beams

This report describes a bilateral comparison of 500 g, 20 g, 2 g and 100 mg stainless steel mass standards between Korea Research Institute of Standards and Science (KRISS) and National Physical Laboratory, India (NPLI), which is registered in the KCDB as APMP.M.M-K2.1. These nominal values were chosen as they followed the nominal values of CCM.M-K2. This bilateral comparison was piloted by KRISS. The Measurement Standard Laboratory (MSL), New Zealand has provided a linkage analysis of this bilateral comparison to CCM.M-K2. The set of four weights was circulated between KRISS and NPLI laboratories in June 2010 and received back from the last participant in July 2010. NPLI has tried to improve their calibration and measurement capabilities (CMCs) for mass below 1 kg. KRISS participated in both this comparison and CCM.M-K2, providing the link between the NPLI results and the key comparison reference value of CCM.M-K2.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 CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).