Simulation and practical realization of the new high precise digital multimeter based on use of dual-slope ADC
✍ Scribed by Predrag Petrovic
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 840 KB
- Volume
- 14
- Category
- Article
- ISSN
- 1430-144X
- DOI
- 10.1002/etep.2
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✦ Synopsis
The measurement method described in this paper can be applied to the accurate determination of AC signals during the period of one second. This paper presents a novel design for a high accuracy multimeter based on the use of very slow, high-precision and cheap dual-slope A/D converters. Measurements of voltage and current are made in successive periods by a stroboscopic technique (synchronous undersampling). The assumed stationarity of the electric utilities is validated by measurements with an experimental set-up consisting of a fast highprecision sigma-delta ADC (1EE Proceedings, Electric Power Applications 1999; 4: 383-390). The necessary synchronization is reached by software measurements of the frequency of the measured signal. Assuming stationarity of the observed system (electric utilities) in the stated one-second interval, it is proved that precise digital processing can be achieved without using a sample-and-hold circuit (IEEE Transactions on Instrumentation and Measurements 2000; 6: 1245-1 248). The suggested measuring system was simulated, practically realized and tested, and the obtained results confirmed completely the starting postulates. Processing precision of 0.01 % was achieved.