Turkish Journal of Electrical Engineering and Computer Sciences




of water has significant importance for industry, agriculture, livestock, and health. The system designed and manufactured in this paper measures, displays, and controls the TDS of water by installation on domestic and industrial purification systems. Technology of manufacturing the TDS measurement system is such that it can compensate for the adverse effect of temperature. Calibration of the measurement system will be explained here by discussion of several examinations conducted at the Research Institute of Food Science and Technology of Iran. In order to control TDS, a mathematical model for domestic water purification devices of reverse osmosis (RO) is obtained using practical experiments. Then the controller is designed by Ziegler--Nichols oscillation and fuzzy logic methods and, after the comparison, a fuzzy logic controller is selected because it shows better response. This controller is implemented using regression analysis, which is a very good method for implementation of fuzzy logic controllers. Operation of controlling the TDS is done through real-time and continuous controlling of a mix valve. This valve is closed in parallel with a membrane filter or RO, so one can control TDS by adding or reducing inlet water into the outlet water of this filter. The system proposed in this research is tested in pilot and has received scientific approval from the relevant authorities.


Temperature turbulence, total dissolved solids measurement, total dissolved solids control, electrical conductivity, fuzzy controller

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