Six channel AC/DC current data logger used in industrial application

Abstract

This paper presents a data acquisition system used for AC/DC current monitoring. The developed system use the current transducer manufactured by LEM [3]. The output signal of the transducer is a voltage that is proportional to the current magnitude. To compute the current, the outputs signal is sampled with high frequency. The AC rms (root mean square) value is obtained by processing the sample values during the multiple periods of alternative signal. The number of periods is chosen according to the dynamic of process. For data acquisition and processing is used a microcontroller, ATMEGA 328. The acquisition system has six input channels, connected at the 10-bit ADC inputs channels of microcontroller. The ADC has ±2LSB absolute accuracy and the sensor accuracy is of ±1 %. The systematic error has a major component into the total error; this error may be reduced, soft, through the calibration process.