Development of a Calibrated Transducer CMOS Circuit for Water Turbidity Monitoring

In this paper, a calibrated transducer CMOS circuit for water turbidity monitoring is proposed. The output signal is a pulse stream. It can be easily broadcast over various digital transmission media. In addition, the proposed calibration method can reduce nonlinear errors arising from turbidity sensors. The turbidity of 8-1011 nephelometric turbidity units corresponded to the output frequency range of 25.3-22.3 kHz. After calibration, measured maximum frequency error was 0.36%.