LESSONS LEARNED FROM REGISTRATION OF OCCUPANCY AND USE OF LIGHTING IN OFFICES, SCHOOLS, UNIVERSITIES AND INDUSTRY BUILDINGS, A CROSS COUNTRY STUDY

The paper presents a registration of occupancy and the use of (day)light in four buildings representing respectively offices, primary schools, universities, and industry buildings; it was done across Europe in 2020. A self-registration method was used, assisted with light technical measurements outdoors and indoors. In general, occupants consider the visual environment at the workplace when they are coming in or out of the room. It happens mainly at the beginning (adjustment of blinds and switching light on) and at the end of the working day (switching light off). In the primary school building, where users move in-out many times during the day, the adjustment happens more frequently. Also use of projector generates very low general light level; covering windows and switching off the electric light happens accordingly, but the pattern is not consistent. In general, the changes in the electrical lighting use follow the occupancy pattern, not the light levels.

TWO-COLOR COMPENSATIVE THERMOMETRY WITH CORRECTED ADJUSTMENT USING NONLINEARITY EQUATION OF EMISSIVITY SPECTRAL DISTRIBUTION

The article is directed on metrological characteristics increase and extension of the optical thermometry field of use, including two-color compensative thermometry with a priori averaged adjustment. The investigations have been performed for the tungsten. This metal studied in thermometry and metal optics has tabulated quantitative estimations of emissivity which are similar to the most widespread in metallurgy iron-carbon alloys. To increase the reliability and extend the field of use of obtained results, approximated and linearized spectral distributions of tungsten, as well as their mirror representations with decreasing and increasing, convex, linear, and concave distributions of emissivity have been researched. The influence of qualitative and quantitative characteristics of the spectral distributions of emissivity on their nonlinearity coefficient has been studied. The equation of nonlinearity has been obtained. This equation connects the nonlinearity coefficient at the middle wave with the emissivity value at one of the boundary waves through the measured one-color radiation temperatures at 3 operating waves. With a priori knew quantitative estimates of the nonlinearity coefficient at the middle wave and measured onecolor radiation temperatures, the obtained equation can be used for the calculation of emissivity values at the boundary waves. For example, in the linear spectral distributions of emissivity, the nonlinearity coefficient is equal to 0. The number of solutions for linear distributions of emissivity varies from 1 to 2, and for nonlinear – from 1 to 3. The influence of measurement errors of one-color radiation temperatures at operating waves on the errors of emissivity determination by nonlinearity equation is established. The metrological advantages of two-color compensative thermometry using the emissivity values, corrected by the nonlinearity equation, are proved. It was found, that at the nonselective distribution of measurement errors of one-color radiation temperatures, measurement errors of the object temperature for two-color compensative, spectral ratio, and energy thermometry are insignificant for technical measurements. Under conditions of selective distribution of measurement errors of one-color radiation temperatures, these errors respectively are 0.04-0.25 %; 1.66-9.30 %; 0.18-0.34 %. For nonlinear emissivity spectral distributions, real for tungsten and iron-carbon alloys, the methodical component due to the nonlinearity doesn’t exceed 0.48 %, which is also acceptable for technical measurements. The method has been developed for practically acceptable conditions of primary pyrometric information obtaining.

Using the phase inversion method and loudness comparisons for the evaluation of noise reduction algorithms in hearing aids

The phase inversion method, a technical measurement procedure, is often used to evaluate the performance of noise reduction algorithms in hearing aids. However, a detailed comparison of these technical measurements with the perceived loudness is missing. Therefore, commercially available hearing aids of six different manufacturers were evaluated technically and in a study with 18 normal-hearing listeners. First, the output signals of the hearing aids with and without activated noise reduction were recorded in a test box. Then, the test subjects evaluated the perceived loudness of these recordings within multiple two alternative forced choice (2-AFC) tasks. During one task, the test subjects had to focus either on the speech or noise signal and were asked to select the louder of two signals, which both contained a mixture of speech and noise. These results provide not only the perceived SNR but also the perceived speech and noise levels. Comparing the results of the 2-AFC tasks and the phase inversion method basically shows good agreement. Nevertheless, a simple computation of the sound pressure level can lead to significant deviations. Therefore, another possibility for the analysis of the results of the phase inversion method to better match the perceived loudness is presented.

Special aspects of the measurement of the internal geometric parameters of the channel parts of small size

Technical measurements of linear-angular sizes of parts and products are the most common in mechanical engineering and make up to 95% of the measurements of all controlled sizes. Measuring control is an integral part of each operation of technological processes of production, assembly, testing of products. The complex method of measuring the external and internal geometric characteristics of a carbide die, given in the article, allows to measure the geometric parameters of small-size parts and to give a final assessment of the product for compliance with the requirements of the project technical documentation.

Activity of All-Russian Research Institute of Physical-Technical and Radio-Technical Measurements (VNIIFTRI) in the sphere of physicochemical measurements

This article presents the description, metrological characteristics and application of State primary standards developed at the All-Russian Research Institute of Physicol-Technical and Radio-Technical Measurements (VNIIFTRI). These include the state primary standards for pH and pX in aqueous solutions, units of the dispersed parameters of aerosols, suspensions and powdery materials, units of the mass fraction and mass (molar) concentration of inorganic components in aqueous solutions based on gravimetric and spectral methods of analysis. In addition, the article discusses R&D projects that are currently being realized at VNIIFTRI, including the production of standard-titres and buffer solutions for pH-metry, as well as working standards for assessing the activity of Na+, K+, F-, Cl-, Br-, I-, NO3-(pX) ions in aqueous media.