Single Chip Impedance Analyzer for Non-Destructive Eddy Current Testing

摘要

In the paper are presented extensions and modifications of the single chip impedance analysers AD5933 and AD5934 for the use in the applications utilizing eddy currents for non-destructive testing. For measurements in a wide frequency band with different probe types it is necessary to extend the standard circuit connection by an precise source of the reference frequency, power amplifier with the low output impedance in the whole frequency band, calibration circuits and an precise current voltage (I/V) converter. Probes with different connection configuration and input impedances were studied for the evaluation of the single chip impedance analyser properties. For the process control was used 32-bit processor ARM Cortex M3 with the possibility of the transmission of measured data to a PC for the further processing and analysis. The control software serves for the base analysis and visualisation of impedance diagrams in the frequency band from 10 Hz up to 100 kHz.