Oxygen Meter Portable Oxygen(O2) Concentration Detector with LCD Display and Sound-light Alarm The portable oxygen detector is a kind of  essential safety instrument which can continuously detect the oxygen concentration in the working environment.It is suitable for explosion-proof, toxic gas leakage, underground pipelines or underground mines and other  places, can  effectively ensure the safety of the staff's life is not  infringed, the production equipment is not lost.    This instrument is a natural diffusion method for detecting gas concentration, using high performance electrochemical sensor, with excellent sensitivity and excellent repeatability.The instrument adopts embedded micro control technology, simple operation, complete functions, high reliability.    This O2 detector is applicable to the concentration of oxygen in the ambient air detection, are widely used in metallurgy, power plant, chemical, mine, tunnel, underground pipelines and other places, effective prevention of hypoxia and oxygen poisoning. Features: Appearance of light and novel, easy to carry, easy to operate.    Menu operation interface, battery power real time display. Under voltage, low voltage automatic shutdown. Rapid response and reliable accuracy. Sound, light and vibration alarm. Specification: Sensor: Electrochemical Principle Test Gases: Oxygen Concentration (O2) Temperature Measurement: Ambient Temperature     Display Unit: O2: %VOL          Temperature: ℃/℉          Measurement Range: O2: 0 ～ 25%VOL              Temperature: -15～50℃ / 5～122℉      Resolution: O2: 0.1%VOL                                                      Temperature: 0.1℃ / 0.1℉  Accuracy: O2: ±3.0%FS                                                            Temperature: ±1.5℃ Response Time: T90<15s                 Alarm: Sound and light vibration alarm     Alarm Point: low alarm point 19.5%VOL                         high alarm point 23.5%VOL            Battery Type: 3 * AAA 1.5V Alkaline Batteries (NOT Included) Operating Temperature: -15～50℃ / 5～122℉      Operation Humidity: 15%～95%RH (non condensation) Item Size: Approx. 12 * 6.5 * 2.5cm / 4.7 * 2.5 * 1.0in (L * W * H) Item Weight: Approx. 107.1g / 3.8oz Package Size: Approx. 22.5 * 11.1 * 5.5cm / 8.9 * 4.4 * 2.2in (L * W * H) Package Weight: Approx. 182g / 6.4oz Package List: 1 * O2 Detector 1 * User Manual