Infrared CO2 Sensor MH-Z1911A User's Manual

Statement

This manual copyright belongs to Zhengzhou Winsen Electronics Technology Co., LTD. Without the written permission, any part of this manual shall not be copied, translated, stored in database or retrieval system, also can't spread through electronic, copying, record ways.

Thanks for purchasing this product. To enable customers to use it better and reduce faults caused by misuse, please read the manual carefully and operate it correctly in accordance with the instructions. If users disobey the terms or remove, disassemble, or change the components inside the sensor, Winsen shall not be responsible for the loss.

Regarding specifics such as color, appearance, and sizes, please refer to the actual product.

Winsen is devoted to product development and technical innovation, reserving the right to improve products without notice. Please confirm you have the valid version before using this manual. User comments on optimized usage are welcome.

Please keep the manual properly for future reference and assistance.

Zhengzhou Winsen Electronics Technology CO., LTD

Profile

The MH-Z1911A infrared CO2 sensor is an intelligent sensor, common type, and small in size. It utilizes the non-dispersive infrared (NDIR) principle to detect the presence of CO2 in the air, offering good selectivity, non-oxygen dependence, and a long lifespan. The sensor features built-in temperature compensation and provides both UART and PWM output. It is developed through the tight integration of mature infrared absorbing gas detection technology, precision optical circuit design, and superior circuit design.

Figure 1: Visual representation of the MH-Z1911A Infrared CO2 Sensor.

Features

• High sensitivity, low power consumption
• Good stability and consistency
• Temperature compensation, excellent linear output
• Multiple output modes: UART, PWM
• Long lifespan
• Anti-water vapor interference, anti-poisoning

Applications

• HVAC system
• Indoor air quality monitor
• Consumer CO2 meter
• Air purifier
• Smart home device

Main Parameters

Detection Range and Accuracy

Appearance and Structure

Figure 2: Diagrams illustrating the physical dimensions and structure of the MH-Z1911A sensor. The top view indicates dimensions of 32.9x19.7 mm with mounting holes. Side views detail height and connector configurations. A perspective view shows the overall assembly with pins.

Pin Definition

Figure 3: Pin Diagram illustrating the layout of pins on the sensor module.

Cautions

1. Please avoid pressure on the optical chamber from any direction during welding, installation, and use.
2. When placed in small spaces, ensure good ventilation, especially for the diffusion window.
3. Keep the module away from heat sources and avoid direct sunlight or other heat radiation.
4. The module should be calibrated periodically; the suggested period is no longer than 6 months.
5. Do not use the sensor in high-dust environments for extended periods.
6. To ensure normal operation, the power supply must be within the 5.0±0.1V DC range, and the power current must be not less than 150mA. Deviations from this range may lead to sensor failure (e.g., low concentration output or complete malfunction).
7. During the zero-point calibration procedure (manual or command-based), the sensor must operate in a stable gas environment (400ppm) for over 20 minutes.
8. Wave soldering is forbidden for this sensor.
9. When soldering with a soldering iron, set the temperature to (350 ± 5) °C, and the soldering time must be within 3 seconds.
10. It is recommended to use sockets for connecting and disconnecting the sensors to facilitate maintenance.