INVARIANT TRANSFORMATION IN MEASURING SYSTEMS WITH PARAMETRIC SENSORS 

Chernetsov Mikhail Vladimirovich, candidate of technical sciences, associate professor, head of sub-department of technical quality management, Penza State Technology University (1a/11 Baydukova avenue/Gagarin street, Penza, Russia), kafedratuk@yandex.ru
Churakov Petr Pavlovich, doctor of technical sciences, professor, sub-department of information -measuring equipment and metrology, Penza State University (40 Krasnaya street, Penza, Russia) iit@pnzgu.ru

621.317

10.21685/2307-5538-2018-1-2

Background. The object of the study are measuring circuits with parametric sensors, described by the circuit of a two-pole electrical circuit, and mathematical models of the invariant transformation algorithm, ensuring the independence of the result of measuring the informative parameter of the sensor from non-informative ones. Important in this case is the definition and mathematical description from the general viewpoint of the realizability conditions of the invariant transformation for sensors whose parameters in the process of the measurement experiment are variable and depend on both the measured physical quantity and the operating conditions. The purpose of the work is to formalize the conditions for ensuring invar iance when measuring the value of the informative parameter of the sensors described by the electric circuit of substitution with variable parameters.
Materials and methods. It is shown that the invariance of the transformation is ensured in a limited observation interval with an admissible error of additive and multiplicative nature due to the influence of noninformative parameters. The analysis of the data of errors and possible ways of reducing their influence on the measurement result in single-channel and multichannel structures of measuring transducers is carried out.
Results. Mathematical models describing the algorithms of invariant transformation in single-channel and multichannel structures of meters with allowance for errors from the influence of non-informative parameters are obtained. The possibility of simplifying the algorithms for transforming the amplitude-time characteristics of the component voltages of the measuring circuits based on the analysis using the test action depending on the topology of the sensor replacement circuit is shown.
Conclusions. The positions of the theory of invariant transformation are developed in the part of refinement of the realizability conditions for measurements of the values of the informative parameters of the sensors described by a twopole electrical substitution circuit with varying parameters. The algorithm for designing circuits of measuring circuits that reduce the errors of a multiplicative nature from the influence of noninformative parameters by selecting the required test action on the sensor is formalized. The analysis of the given examples of construction of circuits of measuring circuits confirms the obtained theoretical results.

invariant transformation, parametric sensor, replacement circuit, measuring circuit, measuring transducer