Specifications: Model: DDS-307A Conductivity Meter Instrument Level: Level 1.0 Measuring Range: (0~1.999)S; (2.0~19.99)S; (200~1999)S (2.0~19.99)mS; Temperature: -5~105 () Basic Error of Electronic Unit: Reference Error of Electronic Unit: 1.0%FS; Temperature Coefficient Display Error: 1.5%/*C Electronic Unit Stability: 0.5 (FS) Temperature Compensation Coefficient: 2.0 (%) Temperature Compensation Range: 0~100 () Power Supply: AC (220 22)V; (50 1) Hz Features: 1. Large screen, blue backlight, double row of numbers, LCD display; 2. Conductivity measurement, resistivity measurement, TDS measurement, temperature measurement; 3. Automatic calibration, automatic range switching, automatic temperature compensation (0 ~ 100 C); 4. Can be connected to electrodes with four constant specifications: 0.01; 10. Package includes: 1*Water quality monitor