Digital EC Meter Water Quality Tester with Measuring Range 0-9990 ppm New Instrument Features: This item can be used in: water purifiers and filters, food (vegetables, fruits) and beverage quality monitoring, swimming pools and spas, aquariums, hydroponics. Hold Function: Saves measurements for convenient reading and recording Measuring Range: 0-9999 ppm Accuracy: ± 2% NW: 23 g Size: 20 x 20 x 150 (mm) Total Dissolved Solids Value Introduction: XPPM: 1 liter of water contains X mg of dissolved solids 0-50, high purity; 50-100, purity higher; 100-300, medium purity; 300-600, will catch the scale; 600-1000, bad taste; Above 1000, not suitable for drinking. Usage Step: Please unplug the electrode protective sleeve before use. Press the switch, place the electrode into the test solution. After the numerically stable, press the button and take it out of the solution to read. After reading, turn off the meter. Wipe the electrode before sheathing it. Package Includes: 1 X Water Quality Tester