Abstracts. № 4, 2015 year
Zhdanov A. (e-mail: alezhd@mail.ru)

Preamplifier-compensator for triaxial vibration transducers

The article describes the structure and operation principles of analogue coupling preamplifier, designed for work with triaxial vibration transducers (TVT). It eliminates measurement errors due to the transducer’s transversal sensitivities. A specially designed TVT with oblique-angled sensitivity vectors` system has been used for testing. It is shown that the proposed preamplifier can almost completely terminate the errors and expand frequency range of both TVTs with orthogonal and oblique- angled sensitivity vectors` systems, thus improving 3D vibration measurement accuracy. The proposed method gives way to creating unique free sensitivity vector`s system TVTs with better metrological properties. It also ensures TVTs` periodical recalibration.

Keywords: triaxial vibration transducer, orthogonalization, transversal sensitivity, 3D vibration, sensitivity vectors system, measurement accuracy.

Demin A.P., Pokrovskiy A.D., Polyakhov M.Yu., Khvostov A.A. (e-mail: pokrovskiy@mail.com)

Intelligent eddy current probe

The results of research in the field of development of microprocessor technology for the eddy current instrument are shown. Most transformation functions are concentrated in the block, combined with the eddy-current probe. The device software, oriented to nondestructive testing of electrically conductive materials is considered.

Keywords: eddy current probe, Fourier transformation, impedance analysis, microcontroller, USB interface, impedance plane diagram.

Prilepko M.Yu. (e-mail: isaev-vm@vniims.ru)

Dynamic calibration method of variable force transducers

The actual calibration methods of dynamic force transducers are considered. The proposed calibration method is based on laser interferometer methods. The short mathematic description of calibration process is presented.

Keywords: calibration, variable forces, sinusoidal exitation, force trancduser, calibration set-up, piezoactuator.

Pirog V.P., Gurskii A.A., Kondratyev I.A. (e-mail: mail@okba.ru)

Measurement of gas-dust streams

There are described methods for automated measurement of temperature, pressure, speed and calculation of volumetric dust rate and mass concentration of the process gases in the dust and gas ducts.

Keywords: parameters of the gas-dust streams, allonge, pneumatic and dust sampling tube, psychrometer.

Korneev R., Tukhvatullin A. (e-mail: rak_1985@mail.ru)

Provision of traceability of measuring instruments of flowrate and amount to State primary standards

The article features the description of structure and characteristics of state calibration hierarchies for measuring instruments of mass and volumetric flowrates (mass and volume) of fluid flow (water), factors determining the uncertainty balance of standards, description of facilities providing the transfer of units from superior standards in cases when unit transfer by direct comparison is impossible.

Keywords: state calibration hierarchy, state primary standard, secondary standards of units of mass and volumetric liquid flowrates (mass and volume), working standards of units of mass and volumetric flowrates (mass and volume) of liquid grade 1 and 2, certification of standards, unit transfer.

Suvorov S.V. (e-mail: ssv-g1@mail.ru)

Random errors in measuring of small gas concentration by an absorption gas analyzer

Some features of signal processing in the measurement of small gas concentration by an absorption type analyzer which selects the operating parts of spectrum through a set of interferential filters are considered. The probabilistic approach to the study of the measurement process is based on a specially introduced auxiliary function. A method of aprioristic estimation of measurement error is proposed which uses the coefficient of the reference signal variation. A procedure of processing two samples of uncentered random variables carrying information about the measured component of the environment is presented. The results of calculating the dispersion and the estimated accuracy of measurement with single and multiple samples are given. The boundary of the proposed approach was indicated as well as a way of reducing the coefficient of the reference signal variation. It is shown that the expected measuring accuracy depends on the duration of measurement process and is achieved by multiple sampling. The influence of random factors on the measurement process was studied. The presented materials could be used as initial in formation of a gas analyzer signal processing algorithm ensuring the validity of the measurement results.

Keywords: absorption gas analysis, random signal, measurement, random error, special measurement features.