ABSTRACT
ABSTRACT: Eddy current (contactless) measurements, especially in the form of the impedance spectroscopy, could be effectively used to determine the electrical properties, including conductivity, of various materials, tissues and objects in many industrial, medical and other applications (e.g. coin validation). One important aspect is to have the calibration standards for the adjustment of eddy current instrumentation to guarantee repeatability and comparability of the measurements. In the paper, there is described an experimental study carried out to find the ways to improve and correct the theoretical eddy current models for the “single coil above the metal plate” setup, designed for measurements without using of the reference metal specimen with known electrical properties. The final results show, that the accuracy of measurement with a single-coil setup can be better than ±0.5% in the 60 to 500 kHz frequency range and ±3.0% at the frequencies up to 10 MHz, all valid for conductivity values from 2.5 to 25 MS/m.
