Zhengzhou Winsen Electronics Technology Co., Ltd Infrared CO2 Sensor Module (Model: MH-Z19C) User’s Manual (Version 1.2) Issue Date. 2021.05.14 Zhengzhou Winsen Electronics Technology Co., Ltd ISO9001 Certificated Company Email: [email protected] Leading gas sensing solutions supplier in China!

Zhengzhou Winsen Electronics Technology Co., Ltd Statement This manual’s 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 our product. In order to let customers use it better 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...

Zhengzhou Winsen Electronics Technology Co., Ltd MH-Z19C NDIR CO2 Module Profile MH-Z19C NDIR infrared gas module is a common type, small size sensor, pins type or terminal type, 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 compensation; and it has UART output and PWM output. It is developed by the tight integration of mature infrared absorbing gas detection technology, precision optical circuit design and superior circuit design. Applications *HVAC refrigeration *Indoor...

Zhengzhou Winsen Electronics Technology Co., Ltd Detection range and accuracy Detection Gas Carbon Dioxide Dimensions(Pins type) Pins connection type: Pin Vin GND PWM Hd Rx Tx Pin Definition Positive pole of power (Vin) Negative pole of power (GND) PWM HD(zero point calibration, low level lasting for over 7s is effective) UART(RXD)TTL Level data input UART(TXD)TTL Level data output Email: [email protected] Leading gas sensing solutions supplier in China!

Zhengzhou Winsen Electronics Technology Co., Ltd Dimensions(Terminal type) Terminal connection type Pin Pin 4 Pin 3 Pin 2 Pin 7 Terminal pin Definition Vin power in GND Reserved PWM HD(zero point calibration, low level lasting for over 7s is effective) UART(RXD)TTL Level data input UART(TXD)TTL Level data output Output PWM output Take 400~2000ppm for example CO2 output range Cycle Cycle start high level output The middle cycle Tel: 86-371-67169097/67169670 Fax: 86-371-60932988 400~2000ppm 1004ms±5% 2ms (theoretical value) 1000ms±5% Email: [email protected] Leading gas sensing solutions supplier...

Zhengzhou Winsen Electronics Technology Co., Ltd cycle end low level output 2ms (theoretical value) CO2 concentration: Cppm=2000×(TH-2ms)/(T-4ms) Cppm: CO2 concentration could be calculated by PWM output TH high level output time during cycle T output time during cycle(1004ms±5%) Serial port output (UART) Hardware connection Connect module’s Vin-GND-RXD-TXD to users’ 5V-GND-TXD-RXD. (Users must use TTL level. If RS232 level, it must be converted.) Software setting Set serial port baud rate be 9600, data bit 8 bytes, stop bit 1byte, parity bit null. 0x86 0x79 Commands Read CO2 concentration Turn...

Zhengzhou Winsen Electronics Technology Co., Ltd For example: CO2 concentration = HIGH * 256 + LOW How to calculate concentration: convert hexadecimal 01 into decimal 1, hexadecimal F4 into decimal 244, then 1*256+244=500ppm 0x79- On/Off Self-calibration for Zero Point Send command-No return value Byte0 Start Byte No return value NOTE: when byte3 is 0xA0, the auto calibration function is on; when byte3 is 0x00, the auto calibration function is turned off. The sensor factory by default is on self-calibration function. Checksum calculation method Checksum = (Negative (Byte1+Byte2+Byte3+Byte4+Byte5+Byte6+Byte7))+1...

Zhengzhou Winsen Electronics Technology Co., Ltd After the module works for some time, it can judge the zero point intelligently and do the zero calibration automatically. The calibration cycle is every 24 hours since the module is power on. The zero point is 400ppm. This method is suitable for office and home environment, not suitable for agriculture greenhouse, farm, refrigerator, etc.. If the module is used in latter environment, please turn off this function. Please avoid the pressure of its gilded plastic chamber from any direction, during welding, installation, and use. When placed in small...