Carbon Monoxide Gas Sensor （Model：MQ-7B） Manual Version: 1.6 Valid from: 2021-07-01 Zhengzhou Winsen Electronics Technology Co.,

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 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 the components inside of the sensor, we shall not...

Zhengzhou Winsen Electronics Technology Co., Ltd MQ-7B Semiconductor Sensor for Carbon Monoxide Profile Sensitive material of MQ-7B gas sensor is SnO2, which with lower conductivity in clean air. It make detection by method of cycle high and low temperature, and detect CO at low temperature (heated by 1.5V).The sensor’s conductivity gets higher along with the CO gas concentration rising. At high temperature (heated by 5.0V),it cleans the other gases adsorbed at low temperature. Users can convert the change of conductivity to correspond output signal of gas concentration through a simple circuit....

Zhengzhou Winsen Electronics Technology Co., Ltd Basic Circuit Fig2. MQ-7B Test Circuit Instructions: The above fig is the basic test circuit of MQ-7B. The sensor requires two voltage inputs: heater voltage (VH) and circuit voltage(VC). VH is used to supply standard working temperature to the sensor and it can adopt DC or AC power. For this model sensor, VH should be at 1.5V±0.1V low voltage when detect CO while should be at 5V±0.1V at non detection status(resuming period). VRL is the voltage of load resistance RL which is in series with sensor. Vc supplies the detect voltage to load resistance...

Zhengzhou Winsen Electronics Technology Co., Ltd Time(s) Fig5.Sensitity Curve Fig5 shows the VRL in CO gas with different concentration. The resistance load RL is 4.7 KΩ and the test is finished in standard test conditions. Fig6.Responce and Resume Fig5 shows the changing of VRL in the process of putting the sensor into target gas and removing it out. Time(day) Fig7.long-term Stability Test is finished in standard test conditions, the abscissa is observing time and the ordinate is VRL. Cautions 1 .Following conditions must be prohibited 1.1 Exposed to organic silicon steam Sensing material will...

Zhengzhou Winsen Electronics Technology Co., Ltd www.winsen-sensor.com 1.4 Touch water Sensitivity of the sensors will be reduced when spattered or dipped in water. 1.5 Freezing Do avoid icing on sensor’s surface, otherwise sensing material will be broken and lost sensitivity. 1.6 Applied higher voltage Applied voltage on sensor should not be higher than stipulated value, even if the sensor is not physically damaged or broken, it causes down-line or heater damaged, and bring on sensors’ sensitivity characteristic changed badly. 1.7 Voltage on wrong pins For 6 pins sensor, Pin 2&5 is heating electrodes,...

Zhengzhou Winsen Electronics Technology Co., Ltd Temperature： ≤350℃ Time：less than 3 seconds If disobey the above using terms, sensors sensitivity will reduce. Zhengzhou Winsen Electronics Technology Co., Ltd Add: No.299, Jinsuo Road, National Hi-Tech Zone, Zhengzhou 450001 China Tel: +86-371-67169097/67169670 Fax: +86-371-60932988 E-mail: [email protected] Website: www.winsen-sensor.com Email: sales@wins