Usage Tips:The MH-Z19E carbon dioxide gas sensor (hereinafter referred to as the sensor) is a general-purpose intelligent small sensor. It has two products: pin and terminal. It uses the principle of non-dispersive infrared (NDIR) to detect CO2 in the air and has good selectivity. No oxygen dependence, long life, etc. The sensor is a high-performance sensor made by closely combining mature infrared absorption gas detection technology with precise optical circuit design and sophisticated circuit design. High sensitivity, low power consumption Excellent stability Temperature compensation, excellent linear output Provide serial port (UART), PWM waveform and other output methods long lasting Anti-water vapor interference, no poisoning Application: HVAC equipment Air quality monitoring equipment Fresh air system Air purification equipment Smart home school Parameters: Product model: MH-Z19E Detection gas: carbon dioxide Power supply voltage: DC(5.0 +/- 0.1)V Average current: less than 40mA (@5V power supply) Peak current: 125 mA (@5V power supply) Interface level: 3.3V (compatible with 5V) Measuring range: 400~5000ppm optional Output signal: serial port (UART) (TTL level 3.3V); PWM Warm-up time: 1min Response time: T90 less than 120s Working temperature: -10℃~50℃ Storage temperature: -20℃~60℃ Working humidity: 0~95%RH (non-condensing) Type: A: Row Pin / B: terminal Colour: As Shown Material: PC+Metal Package Contents: 1 x MH-Z19E IR Infrared CO2 Sensor Module Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.