Combustible Gas Sensor (Model: MH-T7042A) Manual Version: 1.0 Valid from: Zhengzhou Winsen Electronics Technology Co., Ltd.

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 our product. In order to keep customers using 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 the components inside of the sensor, we shall...

MH-T7042A Infrared CH4 Gas Sensor 1. Product Description MH-T7042A is a universal type intelligent sensor to detect CH4 gas, taking advantage of non-dispersive infrared (NDIR) principle. With high selectivity, no oxygen dependence, high performance and long lifespan features, MH-T7042A also has built-in temperature compensation feature. MH-T7042A is a compact and high-performance sensor based on infrared absorption of gas detection technology, micro-machining and sophisticated circuit design. High sensitivity, high resolution, low power consumption Output method: IIC, analog voltage signal, etc....

Molecular Formula Methane CH4 Methane CH4 Methane CH4 Propane C3H8 Chloromethane CH3CL Acetylene C2H2 Ethane CH3CH3 Isobutene C4H10 Gasoline C3-C12 Methanol CH3OH Dichloromethane CH2CL2 Toluene C7H8 Alcohol C2H5OH Oxirane C2H4O Acetic acid CH3COOH Ethyl acetate CH3COOC2H5 With Temperature compensation Note: The range in the above table is the common range, users can customize according to their own needs. Substances that are liquid at room temperature cannot be temperature compensated. Please be careful when selecting. 5. Dimension Drawing (No dimensional tolerance is ±0.2) Figure 2 Dimension...

Shell, grounded UART(RXD) 0-3.0V data input UART(TXD) 0-3.0V data output Vin voltage input Figure 3 Pin definition drawing 6. UART Output Hardware connection Connect the Vin-GND-RXD-TXD of the sensor to the user's 5V-GND-TXD-RXD. (The user end must use TTL level, and if it is RS232 level, conversion must be performed). The detector can directly read the gas concentration value through the UART interface of the sensor, without the need for calculation. Software connection Set the serial port baud rate to 9600, data bit to 8, stop bit to 1, and parity bit to none. Calibrate zero point（ZERO） Calibrate...

0 x87 - Calibrate Zero Point 0 Send Start Byte High span Sensor no return value 0 x88 - Calibrate Span Value 0 Send Start Byte Sensor no return value Checksum & calculation method The checksum = (invert (byte0 +... + byte7)) + 1 For example, Gas Concentration Reading Command Sent Byte0 Start byte Sensor Number Check Value A. Add all the bytes together except byte 0 0x01 + 0 x86 + 0 x00 + 0 x00 + 0 x00 + 0 x00 + 0 x00 = 0x87 B. Get the value from step A, then invert it. 0xFF– 0x87 = 0x87 C. Plus one based on the value of step B 0x78 + 0x01 = 0x79 C Language Calibrate & Calculate and Routine char...

7. Ordering instructions In order to be able to provide a sensor that meets the needs of the customer, the customer is requested to provide the following details. 1. Sensor Model Name. Version Number (A represents the first version, B represents the second version…) Detection channel (1 for single channel, 2 for dual channel...) Gas Type (1 stands for CO2, 4 stands for CH4…) Product appearance series (40 stands for 4R, 70 stands for 7R…) Application Field (T stands for Industrial, Z stands for commercial, V stands for vehicle…) 2. Sensor detection range and resolution (refer to Table 2) 8. Matters...