Brief introduction: It is a mini pocket tester. Widely used for oxygen purity analysis in medical ventilator, anesthesia machine, oxygen concentrator, high-pressure oxygen house and baby care box. It consists of oxygen sensor (oxygen electrode), secondary meters, etc. It is light, strong and portable. Specification: * Working temperature: -10℃ 40℃ * Relative Humidity: = < 90% RH * Power supply: one battery (DC9V) (you need to buy it yourself! ). * Test range: 0-100%, 0-25%, 0-5% * Accuracy ±0.15% (when oxygen is less than 5%) ±0.3% (5%-25%), ±3% (above 50%) * Error: =< 0.01% * Display: integration method, 3 1/2 LCD * Response time: indicates 90% concentration in 10 seconds when the temperature is 20℃ * Precision interfering gas detection: when SO2, NO2, H2S, etc. ≥10%, they will affect the detection precision. * Sensor: electrochemical sensor * Dimension: 160×85×28mm * Weight: 185g ) * Power consumption: 4mw The package includes: 1 * tester