Estimating total dissolved solids (TDS) in a water supply can be effectively achieved by measuring specific conductance. This method is based on the principle that the conductivity of water increases as the concentration of dissolved ions increases. In simpler terms, TDS is comprised of various dissolved ions, including salts and minerals, and these ions carry electrical charge. As the ion concentration rises, so does the water's ability to conduct electricity.
Specific conductance is a rapid and practical means to get an approximate value of TDS because it provides immediate results without requiring extensive sample preparation or lengthy laboratory procedures. Conductivity meters, often portable, allow for on-site testing, making it highly efficient for monitoring water quality.
While other methods such as boiling point elevation can also be used to estimate TDS, they are more complex and less convenient for quick assessments. Visual inspection, while helpful for assessing turbidity or color, does not provide quantitative information about TDS levels. Similarly, pH measurement gives information about acidity or alkalinity but does not directly correlate with total dissolved solids. Thus, specific conductance stands out as the most reliable rapid method for estimating the TDS content in a water supply.