DSP Based Portable Impedance Measurement Instrument Using Sine-Fitting Algorithms

Author

Radii, T. ; Ramos, Pedro M. ; Serra, A. Cruz

Author_Institution

Dept. of Meas., Czech Tech. Univ., Prague

Volume

2

fYear

2005

fDate

16-19 May 2005

Firstpage

1018

Lastpage

1022

Abstract

The development and implementation of a digital signal processor (DSP) based portable impedance measurement instrument is described in this paper. The circuit sinewave stimulus is generated by the device using a direct digital synthesizer at the desired measurement frequency. The sine is applied to a reference impedance in series with the unknown impedance. Two analog to digital converters (ADCs) acquire multiple samples of the two sine voltages which are transmitted to the DSP. Sine-fitting algorithms determine the sine amplitudes, phases, DC components and frequency. From these values and the reference impedance values, the impedance amplitude and phase are determined. Included in the device, amplifiers extend the ADCs input range while a digital potentiometer enables the adjustment of the reference impedance to improve accuracy

Keywords

analogue-digital conversion; computerised instrumentation; digital signal processing chips; electric impedance measurement; potentiometers; DSP based instrumentation; analog to digital converters; digital potentiometer; direct digital synthesizer; impedance measurement; sine-fitting algorithms; Analog-digital conversion; Circuits; Digital signal processing; Digital signal processors; Frequency measurement; Frequency synthesizers; Impedance measurement; Instruments; Signal processing algorithms; Voltage; DSP based instrumentation; impedance measurement; least-squares algorithms; sine-fitting algorithms;

fLanguage

English

Publisher

ieee

Conference_Titel

Instrumentation and Measurement Technology Conference, 2005. IMTC 2005. Proceedings of the IEEE

Conference_Location

Ottawa, Ont.

Print_ISBN

0-7803-8879-8

Type

conf

DOI

10.1109/IMTC.2005.1604294

Filename

1604294