A Cost-Effective Instrument for Measuring Total Dissolved Solids, Electrical Conductivity and Turbidity – A Step towards Sustainable Development

Abstract

Water is an indispensable natural resource which is crucial to the sustenance of human, livestock and plants on the earth surface. It is therefore pertinent to ensure its quality is maintained to acceptable standard. This study presents the design and construction of a cost effective portable instrument for measuring total dissolved solids, electrical conductivity and turbidity of water samples. The work was structured under a three-staged framework comprising system design and construction, calibration and performance evaluation. The hardware integrated an Arduino Uno microcontroller, electrical conductivity and turbidity sensors, with a display module.  Calibration was conducted using standard buffer solutions prepared using Environmental Protection Agency regulations for total dissolved solids and turbidity. Hexamethylenetetramine was diluted with hydrazine sulphate to produce 4000NTU formazin standard solution which was further diluted to other concentrations for turbidity. Pure sodium chloride was also used to produce 1000ppm and 500ppm standard solutions for total dissolved solids measurement. The calibration was done and the error on the sensors were 0.9% and 0.4% for total dissolved solids 1000ppm and 500ppm respectively, also 12.5% and 5% for turbidity standards of 400NTU and 40NTU respectively. This research fills an important gap in water quality monitoring by providing a cost effective, portable, multi-parameter instrument capable of measuring total dissolved solids, electrical conductivity and turbidity in real time. The work contributes to Sustainable Development Goal 6 by providing an accessible tool for real-time water quality assessment, particularly in resource-limited communities. It is a locally reproducible solution for environmental monitoring, public health protection, and community-based water management.