Selection of excitation signals for high-impedance spectroscopy

2013 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium: Measurement Across Physical and Behavioural Sciences

Kowalewski, Michal^1

Gdansk University of Technology, Faculty of Electronics, Telecommunications and Informatics, Department of Metrology and Optoelectronics, Gdansk, Poland^1

关键词: Analog to digital converters;    Estimate accuracy;    Excitation signals;    Impedance spectroscopy;    Impedance spectrum;    Measuring systems;    Response signal;    Technical objects;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/459/1/012060/pdf
DOI  :  10.1088/1742-6596/459/1/012060

来源: IOP

【 摘 要 】

The method of fast impedance spectroscopy of technical objects with high impedance (|Zx| > 1 GΩ) is evaluated in this paper. An object is excited with a signal generated by digital-to-analog converter (DAC) located on the U2531A DAQ module. Response signals proportional to current flowing through and voltage across the measured object are sampled by analog-to-digital converters (ADC) in the DAQ module. The object impedance spectrum is obtained with use of continuous Fourier transform on the basis of acquired signals. Different excitation signals (square, triangle, sawtooth and sinc) were compared in order to estimate accuracy of impedance spectrum evaluation. The method is evaluated by means of simulation and practical experiment in a measuring system on an exemplary object in the form of multielement two-terminal RC network modelling of an anticorrosion coating impedance.