ELECTRICAL IMPEDANCE MEASUREMENT USING PULSE EXCITATION |
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| Abraham Mejía-Aguilar, Ramon Pallàs-Areny |
- Abstract:
- Impedance is the only electrical property common to all materials. Its measurement is used for material characterization and testing, and for sensor design. Impedance measurements in a broad frequency range are slow and need complex instrumentation. Impedance measurements in the time domain can be faster but need more computation power. We propose a novel measurement method intended for applications where the unknown impedance can be modeled by three independent components. The method consists of applying a single pulse, measuring three amplitudes, and calculating the unknown components from the analytical solution of the resulting equation system. The three measurement points are so selected that the computation power needed is minimal. Furthermore, measurements at the leading edge of the pulse are avoided by using linear extrapolation. The method suits lowpower measurements in electrolytes, which involve electrodes that can be modeled by a resistance shunted by a capacitance. Actual conductivity measurements from 100 μS/cm to 10 mS/cm, yield relative errors below 3.5 %, which fulfills the 5 % target set in some standards for monitoring the conductivity of surface water bodies.
- Download:
- IMEKO-TC4-2008-135.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC4
- Event name:
- Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
- Title:
- XVIth IMEKO TC4 International Symposium on Electrical Measurements and Instrumentation (together with 13th IMEKO TC4 Workshop on ADC Modelling and Testing)
- Place:
- Florence, ITALY
- Time:
- 22 September 2008 - 24 September 2008