Design and development of a portable instrument to measure water turbidity

Abstract

This article presents the design and development of a portable electronic device that allows to measure and visualize water turbidity data in the range from 0.1 to 999 NTU using a laser beam. The design of the transducer is based on the ISO 5168: 2005 standard that manages the procedures necessary for the calibration of this type of instruments and the ISO 7027: 1999 standard that relates the turbidity determination process. The design of the instrument, the electronic conditioning of the sensors, the calibration of the device and the measurement results are presented. In the calibration process, the accuracy between 5 and 10% was defined for different ranges of NTU considering a 95% confidence interval. The article emphasizes the analysis used to ensure the reliability of the measurements delivered by the device.