Backlight Model TDS & EC Water Quality Test Pen Meter Conductivity Test Pen 1. LCD large screen display with backlight, easy to cope with a variety of environments 2. Celsius and Fahrenheit units switch 3. Automatic temperature compensation 4. Switch between TDS and conductivity 5. Can be used: for water treatment industry, drinking water industry, family, personal home travel, field work, etc. as a drinking water quality inspection tool Parameters. 1. TDS test range: 0-9999PPM 2. Conductivity test range: 0-9990USCM 3. Temperature range: 0.1-80 degrees Celsius 4. Measurement accuracy: +-2% 5. Battery type: CR2032 button cell 6. Weight: 43 grams 7. Size: 153 x 30 x 14mm Influencing factors. -Water temperature: TDS pen can not be used to measure high temperature water (such as hot boiling water) -Water flow rate: can not be used to measure a large body of water shaking -Region: Each region, city due to different pipelines and water sources, TDS value is different