The article considers the issue of calibration of test and laboratory equipment for reproducing, maintaining temperature and/or humidity and the features of using for this purpose the calibration methodology [1] recommended by the regional metrological organization "EURAMET". The recommended methodology is analyzed and an example of its application is given in order to disseminate the practice of applying this methodology to ensure the unity of measurements when calibrating this category of equipment.

The article discusses methods for reducing the impact of nonlinearity in the transformation function of measurement devices on the accuracy of measurement results by applying an additional correction device that implements a dependency that is inverse to the transformation function. The aim of the research is to explore the possibilities of using artificial neural networks, specifically multilayer perceptrons and radial basis function networks, as such correctors. The effectiveness of the proposed correction methods for the transformation function has been investigated through simulation computer modeling, examining the impact of the type of nonlinearity on the quality of such correction. A comparative analysis was carried out with traditional approaches, specifically a corrector based on polynomial approximation. The simulation results indicate that the accuracy of neural network correctors is comparable to that of polynomial correctors, and in some cases, even superior. This opens up prospects for a broader application of such modern measurement data processing methods as artificial neural networks in measurement technology.

An analysis of the quality indicators of electric energy regulated by European and national standards of Ukraine has been carried out. Factors that affect the quality of electric energy have been studied. Devices that allow for instrumental assessment of the quality of electric energy and their design features have been considered.

Studies of the possibility of using colorimetry in medicine aim to use modern methods and devices for diagnosing the concentration of substances in natural solutions. Colorimetry as a method of measuring the concentration of substances is based on the ability of solutions of certain substances to change color at different concentrations. The method allows quantitatively determining the concentration of a substance based on the color intensity recorded by a device - a colorimeter. The basic principles of colorimetry include spectrophotometry, application of the Bouguer-Lambert-Beer law, calibration of the device, selection of wavelength, assessment of light absorption and comparison with standards. The paper presents the main aspects and principles of colorimetric analysis, which are important for obtaining accurate results.

This paper reportsinformation aboutcalibration ofdigital hygrometers in the range of 10 %rh to 95 %rh. A procedure has been developed in the NPP “Temperature measurements” Laboratory. The hygrometers has been calibrated against the standard digital hygrometer with metrological traceability to SI units. The process of obtain the reading of standard hygrometer is automated. The measurement model relating the input quantities with output quantity has been developed. Paper also describesthe details of estimation and expression the expanded uncertainty of measurement. The laboratory demonstrates its measurement competence in relative humidity area by participation in the proficiency testing scheme by interlaboratory comparison BIM-T-RH-2023-01. The results are presented and analyzed.The aims of this comparison are to evaluate the performance of laboratories and to confirm their technically competence in the field of relative humidity measurements.

The use of ultrasound in the flame-photometric determination of sulfate-ions in water by the indirect potassium method was studied. At the same time, precipitation of sulfate ions was carried out with an excess of slightly soluble dry potassium barium phosphate salt. It is shown that the amount of potassium that has passed into the solution is proportional to the amount of sulfate ions in the analyzed sample. To improve the reproducibility and correctness of the obtained results, as well as to increase the expressivity of the analysis, the precipitation of sulfate ions was carried out under the influence of ultrasound with a frequency of 5.0 - 7.0 MHz, an intensity of 3.0 - 5.0 W/cm2 for a period of time ≥ 2,0 min. A method for determining sulfate ions in waters with mineralization up to 50 g/l has been developed, the range of determined concentrations of sulfate ions is 10 – 150 mg/l. The correctness of the obtained results (determined using standard water samples UkrNDIsil CRM 022.3-20s, CRM 022.3-20m and CRM 022.3-20vm) was for water with mineralization of 50 g/l - 92.5 - 93.1%, and for water with mineralization up to 10 g/l - 99.2 - 99.6%. The relative standard deviation of the analysis results did not exceed 0.051. Without the use of ultrasound, the quantitative determination of the content of sulfate ions is possible only in waters with mineralization up to 10 g/l with an accuracy of 90.2 - 91.0%.

A variant of the method for solving one of the problems of pedagogical qualimetry is considered, the essence of which lies in the use of an assessment model in the form of a set of a four-point scale of the order of several varieties, a two-point scale, a rating hundred-point scale and the corresponding ECTS scale, which allows comparing the grades obtained on any of these scales and applying them to assess the level of preparedness of subjects of study for a certain type of professional activity.

When organizing metrological activity at an enterprise, the question arises of the need to organize verification (metrological confirmation) of measuring equipment that is not used in the field of legislatively regulated.
 In the international standards «Quality Management Systems» (ISO 9001, EN 9100, AQAP-2110), to ensure that the requirements of Section 7.1.5 «Resources for Monitoring and Measurement» are met, the requirement is established that all measuring equipment, as part of a measurement management system, must have metrological confirmation in accordance with the requirements of ISO 10012.
 Metrological confirmation provides for the calibration and verification of measuring equipment.
 Laboratory specialists who carry out metrological confirmation of measuring instruments, establish a relationship between the values of the values that provide the standards, and the result of measuring this quantity using measuring instruments (carry out calibration), based on this ratio establish the conformity / non-compliance of the measuring instruments with the established requirements (carry out verification) and draw up the corresponding supporting document.
 After comparing the concepts of metrological confirmation and verification of measuring instruments, we can conclude that metrological confirmation (calibration and verification) of measuring equipment is essentially nothing more than verification of measuring instruments.
 Metrological activities to ensure the uniformity of measurements in enterprises should comply with the requirements of ISO 10012: 2003. This standard establishes general requirements and contains recommendations for the management of measurement processes and metrological confirmation of the suitability of measuring equipment, which is used to maintain and demonstrate compliance with metrological requirements.
 Compliance with the requirements set forth in the ISO 10012 standard makes it possible to ensure compliance with the measurement requirements and the management of measurement processes established by the international standards «Quality Management Systems».

The control parameters of metal products using the eddy current method of nondestructive testing based on electromagnetic induction law is now widespread. Due to the high sensitivity over a wide frequency range of the ability to control the mechanical properties , uniformity of material, both magnetic and non-magnetic materials, beskonechnosti, high reliability, automation, process control, etc.
 The object of study is the process of interaction of external electromagnetic fields with defects in heterogeneity of structure in metal rod, causing a deformation of microtubuli currents and, accordingly, their influence on the inductance coil of the sensor. So, according to the law of electromagnetic induction eddy currents induced by an external electromagnetic field will be asking a private field that will oppose the external field that will lead to a change in inductance of the sensor coil. Therefore, the most informative parameter in this case is the relative change in inductance of the sensor.
 In the known designs use differential transformer sensors, transmission type, which differ in complexity of implementation, but have high sensitivity. In existing works not enough attention on improving of the metrological characteristics . Modern means of microstraava flaw detectors in the overwhelming number are for scientific research, but little attention is paid to tools that can be used in industrial processes, through a complex measurement process in the existing funds and the large volume of the software during automatic processing of information.
 In the presented work there is a system for nondestructive testing of metal bars with deprivation of the above-mentioned disadvantages, which would provide high metrological characteristics in a wide frequency range, separate measurement of impedance components of the sensor, which allows the reduction of methodological errors of determination of the main characteristics of the output signal of microstraava sensors.
 The scientific result is created sambalanco pavement system based on electronic dharamtala model of a vortex sensor with high metrological characteristics, which allows you to create real-time signal proportional to the amount of damage that will give you the opportunity to increase productivity in the quality control bar of metal products in a production environment.

Reference method for simultaneous calibration of the three and more measurement standards for vertical angle measurement is developed. This method can to use for obtaining the systematic biases of the vertical angles measurements for each of the measuring standards relative of the horizontal plain was averaged from measurement results in time their calibration or comparison. For realization of the reference method was developed the autocollimationel electronic measurement standard for the automatization measurement of the vertical angles SeaLineZero_Standard™ (SLZ_S™). Summary standard deviation (k=1) of the vertical angle measurement relative the horizontal plane, from the results of their calibration by reference method, is not more 0,07ʺ…0,15ʺ. This result was obtained without the use the systematic biases, for each measurement standards, as measurements corrections (with opposite sign). The measuring standards, that were developed and researched, are necessary for obtaining the systematic biases of the vertical angle measurement for total stations and theodolites, that have the normed standard error 0,5ʺ and 1ʺ, when these instruments are calibrating.