Meter Digital Tester Home Drinking Tap Water Quality Test Tester Instrument features: This item can be used in : water purifiers and filters, food (vegetable, fruits) & drink quality monitoring, pools and spas, aquariums, hydroponics. Hold function : Saves measurements for convenient reading and recording Frosted translucent shell, backlit HD display Measurement Range:0-9999ppm Accuracy: ± 2% NW:70g Size:15.5x14x250(mm) Total Dissolved Solid value introduction: XPPM: 1 liter of water contains X mg of dissolved solids 0-50, high purity; 50-100, higher purity; 100-300, average purity; 300-600, will catch scale; 600-1000, poor taste; Above 1000, not suitable for drinking. Use 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 of the solution to read. After reading, turn off the meter.wipe clean the electrode before sleeving it. Package include： 1 X Water Quality Tester