Infrared Carbon Dioxide Module (Model: MH-Z14B) User’s Manual V1.1 Valid from June 18th,2021 Zhengzhou Winsen Electronics Technology CO., LTD.

Statement The copyright of this manual 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 our product. In order to enable customers to better use the product and reduce the 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, change the components inside of the...

Zhengzhou Winsen Electronics Technology Co., Ltd MH-Z14B NDIR CO2 Module 1. Profile MH-Z14 NDIR Infrared gas module is a common type, small size sensor, using non-dispersive infrared (NDIR) principle to detect the existence of CO2 in the air, with good selectivity, non-oxygen dependent and long life. Built-in temperature sensor can do temperature compensation; and it has digital output and analog voltage output. This infrared gas sensor is developed by the tight integration of mature infrared absorbing gas detection technology, Precision optical circuit design and superior circuit design. 2....

Zhengzhou Winsen Electronics Technology Co., Ltd Detection range and accuracy Target Gas Carbon Dioxide (CO2) Power positive(Vin) Power negative(GND) HD (Zero calibration, keep low electrical level for more than 7 seconds)) UART（RXD）data input UART（TXD）data output Email: [email protected] Leading gas sensing solutions supplier in

Zhengzhou Winsen Electronics Technology Co., Ltd 7. Output PWM output (taking 2000ppm PWM output as example): CO2 output range: 0ppm-2000ppm Cycle: 1004ms±5% High power output for beginning: 2ms (Theoretical value) Middle of cycle: 1000ms±5% Low power output for ending: 2ms（Theoretical value） Account formula for CO2 concentration which gets through PWM: is calculated CO2 concentration, unit is ppm; TH is time for high level during an output cycle; TL is time for low level during an output cycle. UART output Hardware connection: Vin-5V power GND- GND RXD connect sensor TXD TXD connect sensor RXD...

Zhengzhou Winsen Electronics Technology Co., Ltd Command Each command or return： Contains 9 bytes (byte 0 ~ 8) Starting byte fixed 0 XFF Command contains sensor number (factory default to 0 x01) to check and end Command List: 0x86 Calibrate zero point（ZERO） Read gas concentration Send command Byte0 Return value Return Byte0 Gas concentration= high level *256+low level Example: Convert hexadecimal to decimal: 01 is 01, F4 is 244; CO2 level:01*256+244=500ppm Checksum calculation method Checksum = (Invert (Byte1+Byte2+Byte3+Byte4+Byte5+Byte6+Byte7))+1 For example： Byte0 Starting byte Check value...

Zhengzhou Winsen Electronics Technology Co., Ltd char get CheckSum (char *packet) { char i, checksum; for ( i = 1; i < 8; i++) { checksum += packet[i]; } checksum = 0xff – checksum; checksum += 1; return checksum; } Zero Point Calibration: In order to facilitate the user to calibrate the zero point, the sensor has two zero calibration methods: manual zero calibration and command zero calibration. The zero point calibration function refers to calibrating 400ppm. ①Manual zero point calibration Manual zero point calibration is to input low level (0V) to the HD pin of the sensor to calibrate zero...

Zhengzhou Winsen Electronics Technology Co., Ltd diffusion windows should be in a well-ventilated position.  The sensor should be far away from heat sources and avoid direct sunlight or other heat radiation. The sensor should be calibrated regularly, and the calibration period is recommended to be no more than 6 months. Do not use the sensor for a long time in an environment with high dust density. In order to ensure that the sensor can work normally, the power supply voltage must be maintained in the range of (5.0±0.1)V DC, and the power supply current must not be less than 150mA. If it is...