Features:  It is used for analyzing the purity of oxygen in respirator machine of medical treatment and anesthesia machine and oxygen concentrator and high-pressure oxygen house and the nursing case keeping infant.  Instrument sensor is electrochemistry diaphragmatic positron.  It makes use of platinum negatron and silver and silver chloride as electrolyte.  Diaphragmatic material is polyethylene film which chooses the permeating oxygen.     Specification:  Product Name: digital oxygen measuring instrument;  Range: 0-100% 0-50% 0-1%;  Accuracy: ± 0.10%;  Use ambient temperature: -20~ 50 °C;  Humidity: <90%;  Use: hand pinch suction type;  Resolution: 0.01%;  Response time: 10 seconds to indicate 90% of oxygen concentration (at 20 ° C);  Power consumption: 4 mW;  Power: 6F229V(not included);  laminated battery, can work for 500 hours;  Affect the detection accuracy of interference gas: SO2, NO2, H2S ≥ 10% when the impact of the determination;  Dimensions: 23x18x7cm/9.06x7.09x2.76in.     Package includes:  1 * Oxygen analyzer;  1 * Oxygen sensor;  1 * White filter hose;  1 * Black suction ball;  1* Portable carry bag.     Note:  Transition: 1cm=10mm=0.39inch.  Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid.  Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you