EVALUATION REDUCED ERROR WHEN CONSTRUCTING A QUASI-DIFFERENTIAL MEASURING CIRCUIT PRIMARY EDDY CURRENT PROBES

Abramov Sergey Vladimirovich, postgraduate student, Penza State University; engineer, Scientific-research Institute of physical measurements, abramov2011s@mail.ru

621.3.014.14:621.3.088

The paper deals with a separate independent measurement of the parameters of the primary eddy current transducer. A scheme for the replacement of the primary eddy current converter in a parallel connection with the initial inductance series connection of active and reactive component insertion resistance. This equivalent circuit is derived from the experimental determination of the amplitude and phase characteristics of the conduction of the primary eddy current transducer. The model of the primary eddy current transducer allows more fully and purposefully address issues of construction of converter Only with the transformation of informative parameters of equivalent circuit parameters and compensation of noninformative and uninformative eliminating the option to improve the conversion accuracy (measured) object movement control. Proposed circuit solution to eliminate non-informative parameter using a quasi-differential circuit switching. Estimated conversion reduced error of measurement information parameter (motion) at partial compensation of non-informative parameters and mathematical expression is obtained that allows to evaluate the undercompensation in amplitude and phase, and thus meet the requirements specified by the value given error. The article is also determined, that the accuracy of temperature compensation to the measurement result determined movement strictly identical parameters branches and strictly identical dependence of these parameters on the temperature over the entire operating range.

primary eddy current sensors, the quasidifferential scheme, the given error, equivalent circuit.