TDSscan20 is a multi-range pocket TDS tester that suitable for measuring the Total Dissolved Solids of liquids. By measuring the TDS values of liquid, you can determine the water purity, or mineral levels in the water.   Features: Standard platinum sensor provides fast and reliable measurements. Up to 3 points calibration allows user to uses customized calibration     solutions. Adjustable TDS conversion factors. Automatic Temperature Compensation ensures highly accurate     measurements over the entire range. Hold function freezes the current displayed value for easy viewing     and recording. Setup menu lets user customize calibration points, temperature unit,     automatic or manual hold function to meet personal preferences. Reset feature allows user to resume all of the default settings. Auto-power off feature helps you effectively conserve battery life. Replaceable electrode reduces maintenance and replacement cost. Waterproof feature to ensures complete protection in harsh     environments.