WMO Interlaboratory Comparison in Europe with Loops Linkage and Data Processing

This article describes the interlaboratory comparison (ILC) of meteorological and hydrological calibration laboratories in the field of temperature (−30° to 40°C), humidity (10%–95% RH at room temperature), and pressure (800–1100 hPa). The ILC was organized by the World Meteorological Organization (WMO) Regional Instrument Centre (RIC) at the Slovenian Environment Agency and University of Ljubljana, Faculty of Electrical Engineering, Laboratory of Metrology and Quality as an accredited interlaboratory comparison (proficiency testing) provider according to the ISO/IEC 17043:2010 standard. The ILC was organized in the target area of WMO Regional Association VI (Europe). The protocol and procedure for ILC were developed within European Metrology Research Project (EMRP) MetoMet2. The participants used their standardized procedures for calibration. Because of the large number of participating laboratories (18) from 17 countries, the ILC was organized in two loops, which were linked via four linking laboratories and evaluated using the En number. The equipment used in both loops exhibited stability and uncertainty, which enabled evaluation of the laboratories’ capabilities. The article presents the data processing, the linkage procedure, and the main results for all three categories (temperature, humidity, and pressure). It was observed that some of the laboratories had unusually low uncertainties. From the metrological point of view, the authors present some comments and suggestions to the laboratories, the results of which differ from the reference ones. The conclusions can help also other meteorological laboratories and organizations that did not participate in the ILC with their everyday work.

VALIDASI SISTEM KALIBRASI HIDROMETER MENGGUNAKAN METODE CUCKOW MELALUI PROGRAM INTER-LABORATORY COMPARISON

Laboratorium densitas Pusat Penelitian Metrologi – LIPI telah melakukan validasi sistem kalibrasi hidrometer melalui uji banding internasional atau inter-laboratory comparison secara bilateral dengan Laboratoire National de Métrologie et d’Essais – Perancis. ILC dilakukan untuk rentang ukur hidrometer 600 kg/m3 ~ 2000 kg/m3. Metode yang digunakan dalam sistem kalibrasi hidrometer adalah metode Cuckow dengan 2 buah hidrometer standar dari jenis milk hydrometer yang berentang ukur 1025 kg/m3 ~ 1037 kg/m3 dan alcoholometer yang berentang ukur 90 % vol/vol ~ 100 % vol/vol, nilai densitas sekitar 800 kg/m3 sebagai artefak. Cairan acuan yang digunakan yaitu tridecane (C 13H28) yang tertelusur ke solid glass sphere milik P2M – LIPI. Validasi dilakukan dengan membandingkan hasil pengukuran P2M – LIPI dengan LNE. Berdasarkan analisis En number, diperoleh nilai antara -0,09 sampai -0,65 untuk semua titik pengukuran, sehingga dapat disimpulkan bahwa sistem dan metode yang digunakan P2M – LIPI untuk mengalibrasi hidrometer memiliki hasil pengukuran yang setara dengan negara lain.

PENENTUAN NILAI ACUAN UJI BANDING ANTAR LABORATORIUM KALIBRASI UNTUK KALIBRASI MIKROPIPET BERDASARKAN KONSENSUS

<p>Abstrak<br />Dalam uji banding antar laboratorium kalibrasi yang terakreditasi, nilai acuan yang digunakan umumnya dikeluarkan oleh laboratorium metrologi nasional yang bertindak sebagai laboratorium acuan. Tetapi dalam beberapa kasus uji banding, laboratorium metrologi nasional kemungkinan tidak dapat mengeluarkan nilai acuan untuk uji banding karena artefak yang digunakan berada pada level industri, sehingga harus dilakukan cara lain untuk menetapkan nilai acuan. Tulisan ini memaparkan penetapan nilai acuan uji banding berdasarkan konsensus dengan contoh kasus uji banding mikropipet pada nilai nominal 100 μL dan 500 μL menggunakan beberapa pendekatan statistik sebagai estimator. Estimator yang dipilih disesuaikan dengan kondisi data hasil uji banding. Untuk memvalidasi metoda yang digunakan, nilai acuan dari estimator yang dipilih dibandingkan dengan nilai hasil kalibrasi yang dikeluarkan Puslit Metrologi LIPI. Berdasarkan analisis En number diperoleh nilai 0,31 dan 0,21 untuk masing-masing nilai nominal, sehingga dapat disimpulkan bahwa metoda yang digunakan dapat dipertanggungjawabkan..<br />Kata kunci: uji banding, nilai acuan, konsensus, mikropipet.</p><p><br />Abstract<br />In the laboratory comparison between accredited calibration laboratories, generally the reference value used is issued by national metrology laboratory act as reference laboratory. But in some cases, the national metrology laboratory may not provide the reference value for comparisons because of artifacts that are used at the level of the industry, therefore it should be done by another way to determine the reference value. This paper describes the determination of the reference value based on consensus of micropipette laboratory comparison as example cases on the nominal value of 100 μL and 500 μL use several statistical approaches as an estimator. The selected estimator adapted to the conditions of laboratory comparison data. To validate the method used, the reference value of the selected estimator compared with the value of the calibration results issued by Research Center for Metrology LIPI. Based on the analysis of En number, values obtained were 0.31 and 0.21 for each of the nominal value, therefore it can be concluded that the method used is reliable<br />Keywords: laboratory comparison, reference value, consensus, micropipette.</p>

The Distribution of Early Recombination Nodules on Zygotene Bivalents From Plants

Early recombination nodules (ENs) are protein complexes ~100 nm in diameter that are associated with forming synaptonemal complexes (SCs) during leptotene and zygotene of meiosis. Although their functions are not yet clear, ENs may have roles in synapsis and recombination. Here we report on the frequency and distribution of ENs in zygotene SC spreads from six plant species that include one lower vascular plant, two dicots, and three monocots. For each species, the number of ENs per unit length is higher for SC segments than for (asynapsed) axial elements (AEs). In addition, EN number is strongly correlated with SC segment length. There are statistically significant differences in EN frequencies on SCs between species, but these differences are not related to genome size, number of chromosomes, or phylogenetic class. There is no difference in the frequency of ENs per unit length of SC from early to late zygotene. The distribution of distances between adjacent ENs on SC segments is random for all six species, but ENs are found at synaptic forks more often than expected for a random distribution of ENs on SCs. From these observations, we conclude that in plants: (1) some ENs bind to AEs prior to synapsis, (2) most ENs bind to forming SCs at synaptic forks, and (3) ENs do not bind to already formed SCs.