For optimal performance, re-calibrate your meters periodically or if testing TDS or conductivity levels in wide or different ranges.
The 342ppm Calibration Solution is designed for use with pure drinking water. The 1000ppm Calibration Solution is designed for use with beverages, aquariums and pools.
The 342ppm Calibration Solution is designed for use with pure drinking water. The 1000ppm Calibration Solution is designed for use with beverages, aquariums and pools.