Which solutions are used to calibrate the TDS meter?

The calibration of a Total Dissolved Solids (TDS) meter is crucial for accurate measurements, and the solutions used for this purpose should be chosen based on the expected range of TDS levels in the samples being tested.

The concentrations provided in option B—1500, 150, and 15—create a range that covers different levels of TDS, from low to high. This diversity in calibration standards allows for precise adjustments to the meter, ensuring that it can accurately measure various concentrations of dissolved solids in water.

Calibration with these specific solutions can help users ensure that the meter is functioning properly across a typical range of dissolved solids that might be encountered in freshwater, brackish water, or even seawater samples. By using solutions that reflect actual conditions, users are more likely to achieve reliable and valid readings in practical applications.

Other options do not effectively cater to a range that includes both lower and higher TDS values, which is essential for comprehensive calibration and accuracy in real-world usage.