DO9100 Portable Digital Dissolved Oxygen Meter with Temperature Detector for Aquarium Swimming PoolBacklight Item Type: Dissolved Oxygen Meter Material: ABS Model: DO9100 Battery: 1.5V LR44 x 3 Battery (Battery Not Included) Uses: Suitable for freshwater aquaculture, marine aquaculture, swimming pools, beverage factories, sewage treatment plants, laboratories. Measuring Range Oxygen concentration (mg/L) 0.0-40.0mg/L Dissolved Oxygen Saturation (%) 0.0-300.0% Temperature 0.0-40.0℃ 32.0-104.0℉ Resolution Oxygen concentration (mg/L) 0.1mg/L Dissolved Oxygen Saturation (%) 0.10% Temperature 0.1°C; 0.1°F Accuracy Oxygen concentration (mg/L) ±1.5%F.S Dissolved Oxygen Saturation (%) ±1.5%F.S Temperature ±0.5℃ Calibration Mode Support single point or double point automatic calibration, that is, zero point or automatic 100% calibration in air Response Time ≤45s (response at 20℃) Temperature Compensation Range Automatic (0-40℃) Height Compensation Without Battery Power Low battery warning Shut Down Automatic shutdown about 15 minutes Use Environment 0.1-40.0℃ RH maximum 90%