1.Microprocessor technology 2.Dot-matrix LCD 3.Auto temp compensation 4.calibration of zero oxygen 5.dissolved oxygen meter Characteristics:   1. Microprocessor technology. Dot-matrix LCD with blue-light.   2. With the functions of automatic temperature compensation and  calibration of zero oxygen, full scale, atmosphere pressure and salinity   3. With the function of double displays of dissolved oxygen concentration value and temperature, dissolved oxygen saturation value and temperature   4. With Measuring results can be stored, deleted, cousulted and printed. At most 50 sets of data can be stored. the user can two ways to select immediate printing or storage printing.   5. The meter has the function of protection from electricity cutting off;   6. With RS-232 interface which is connected and with Model TP-16 printer to print measuring results or connected with computer to communicate;   7. Using 1.1 communication soft can connect with computer Specifications: 1. Measurement range:      Dissolved oxygen: 0.00-20.00 mg/L     Dissolved oxygen saturation: 0.00-200.0 %     Temperature: -5.0-105.0°C 2. The range of automatic temperature compensation: 0-40°C 3. Accuracy:     Dissolved oxygen:     ±0.3 mg/L± 1 bit (under the basic temperature)    ±0.5 ml/L± 1 bit (differ: ±15°C from the basic temperature)     Dissolved oxygen saturation:    ±5%± 1 bit (under the basic temperature)    ±10%± 1 bit (differ: ±15°C from the basic temperature)    Temperature: ±0.5°C ± 1 bit (0°C £T £ 60°C)                       ±1.0°C ± 1 bit (on the other temperature range) 4. Remaining current: ≤0.15mg/L 5. Response time: 45s (90% response on 20°C) 6. Salinity calibrating range: (0.0~40.0)g/L 7. Repeatability of the meter: ≤0.2mg/L. 8.Stability of the meter: not over ±0.2mg/L within one hour.