This paper presents the results of a study on the development of alumina-based porosity reference materials (RMs), which are intended for controlling the accuracy of the measurement results obtained using the mercury porosimetry method. These mercury porosimetry RMs are being developed in the Russian Federation for the first time and are primarily intended for verification / calibration and testing for type approval of mercury porosimeters. The study of metrological characteristics was conducted using a reference system, which is to be included in the GET 210-2014 State Primary Measurement Standard for units of specific gas adsorption, specific surface area, specific volume and pore size of solid substances and materials. This reference system was calibrated prior to conducting the study with the use of external reference pressure sensors of the 2nd order at 0.6 MPa and 400 MPa, as well as a laboratory balance (special accuracy class 1) having a maximum weighing limit of220 g. In the course of conducted research work, procedures for reproducing and estimating the uncertainty of porosity characteristics using the mercury porosimetry method were developed. When estimating the PM metrological characteristics, the standard uncertainty, associated with the characterisation and heterogeneity of the studied materials (PM candidates), was evaluated. The standard uncertainty due to instability was disregarded due to the high stability of the alumina matrix. According to the results of the conducted studies, four types of alumina-based porosity PM were developed. Their pore sizes are of about -lOnm; -2,000 nm; -9,000 nm; -60,000 nm. The RMs with pore sizes of -10 nm; -2,000 nm were intended for use in controlling the accuracy of mercury porosimeters operating at high pressures, while the RMs with pore sizes of -9,000 nm; -60,000 nm were for controlling the accuracy of mercury porosimeters operating at low pressures. The developed RMs are different from their foreign counterparts, which are produced by BAM (Germany) and NIST (USA) metrological institutes. The standard uncertainty due to characterisation of the RMs in question was estimated, not by the method of interlaboratory experiment, but by a full analysis of the constraint equations taking into account all sources of uncertainty included in the equations on the basis of the Guide to the Expression of Uncertainty in Measurement. The conducted studies allowed the RM certified values to be traceable at this stage to the GET 3-2008 State Primary Measurement Standard for the mass unit (kilogram), the GET 101-2011 State Primary Measurement Standard for the pressure unit in the field of absolute pressure in the range 1×10^–1– 7×10⁵ Pa, the GET 43-2013 State Primary Measurement Standard for the pressure unit in the range 10-1600 MPa and the effective area of the piston-cylinder unit of dead weight testers in the range 0.05-1 cm^2. In addition, a reference material having a large pore size of -60,000 nm, which currently has no analogues elsewhere in the world, was characterised.

For the metrological assurance of the high-precision inductively coupled plasma (ICP) mass spectrometry and optical emission spectroscopy methods, the All-Russian Scientific Research Institute for Optical and Physical Measurements (VNIIFTRI) has launched works on the development of reference materials (RMs) of the mass fraction of metals in solutions specifically intended for measurements using inductively coupled plasma methods (ICP-CRM). The ICP-CRM under development was represented by a solution with the certified value of the lead mass fraction. The ICP-CRM was packed in high-density polyethylene bottles with the capacity of 4, 8, 15, 30, 60 and 125 cm³. The certified value of the lead mass fraction in the solution was established by the preparation method and confirmed by the GET 217-2018 State Primary Standard for units of the mass fraction and mass (molar) concentration of inorganic components in aqueous solutions based on gravimetric and spectral methods. The permissible certified values of the lead mass fraction in the developed ICP-CRM are shown to range from 800 mg / kg to 1200 mg / kg. The uncertainty in the certified value is expressed as expanded uncertainty, U = 0,5 % at 95 % confidence, and is calculated in accordance with ISO/IEC 17025 according to GUM (Guidelines to Uncertainty in Measurement). The developed ICP-CRM solution of the lead mass fraction can be used for ensuring the metrological traceability of measurements in inorganic analyses using ICP-MS and ICP-OES to the GET 217-2018.

The authors provide information on the need to develop a reference material (RM) of the southern middle loamy black soil certifiedfor fertility indicators. The information about the stages of RM development is described: selection and preparation of soil material in the field; procedure of averaging soil material.

In the determination of the RM metrological characteristics, the heterogeneity and stability characteristics of the RM are evaluated.

The authors demonstrated the results of the RM certification for agrochemical indicators. The correctness of these results is confirmed by the results obtained in twenty-three accredited laboratories.

The developed RM is registered in the State Register of the Approved Types of Certified Reference Materials under the number GSO 11369-2019-the RMfor composition (of agrochemical indicators) of the southern middle loamy black soil (SACHyuzhP-02).

The RM is intended for metrological support of agroecological monitoring of agroindustrial complex laboratories.

 

This article is timed to coincide with the end of the celebration of the International Year of the Periodic Table of Chemical Elements, declared by the UN and UNESCO in connection with the 150th anniversary of the discovery by D. 1. Mendeleev of the Periodic Law of Chemical Elements. The article highlights metrological activity of the great Russian scientist and encyclopedist and tells about how in the scientific metrological centre, he created- the Main Chamber of Weights and Measures, now D. 1. Mendeleev VNllM (VNllM), the memory of the life and activities of the first administrator of the Main Chamber of Weights and Measures Weights has been preserved for more than a hundred years. Based on research, carried out in the archives of St. Petersburg and the funds of Metrological Museum, the article for the first time details the history of the formation of the Mendeleev memorial complex on the territory of VNIIM. The contribution of the institute metrologists to the creation of such famous sights of St. Petersburg as the monument to D. 1. Mendeleev (the work of the sculptor 1. Ya. Ginzburg, 1932) and the mosaic panel « D. 1. Mendeleev Periodic system of elements «(1935) on the occasion of the 100th anniversary of the scientist is shown. All peripetias, related to the installation of the monument table are described: selection of options for the arrangement of elements, decoration, manufacturer and manufacturing techniques, coordination with various organizations, solving financing issues.

The article presents the results of studying of nuclear magnetic relaxation characteristics of protons, which contain in various organosilicon fluid brands, with the aim of justifying the possibility of their use in the development of simulator reference materials (RMs) of oleic acid mass fraction in sunflower seed oil. The data characterizing the NM-relaxation characteristics of organosilicon liquids, varying in a viscosity index, are provided. Based on the range of changes in the time of spin-spin relaxation of protons containing in oil of sunflower seeds with various mass fraction of oleic acid (157-200 msec) there are select silicon organic fluids, that allow the most accurate simulation of wave-form envelopes of oil protons spin echo signals in the seeds. The simulator reference materials under development are intended for use in the calibration of NMR-analyzers for determination of oleic acid mass fraction in of sunflower seed oil.

In this article, the author proposed a method for estimating the consensus value of interlaboratory measurement results, which makes it possible to reduce the uncertainty of the consensus value in comparison with the known methods. The method is based on the selection of the largest consist subset of the results, the uncertainties of which do not increase when calculating the agreed value in the inconsistent data.