MQ-7 CO Carbon Monoxide Coal Gas Sensor Module detects the concentrations of CO in the air and outputs its reading as an analog voltage. The sensor can measure concentrations of 10 to 10,000 ppm. The sensor can operate at temperatures from -10 to 50°C and consumes less than 150 mA at 5V.
This module provides both digital and analog outputs. The threshold level for digital output can be easily adjusted using the preset on the board. The MQ-7 sensor module can be easily interfaced with Microcontrollers, Arduino, etc.

Features
- The Analog Output Voltage, the higher the concentration the higher the voltage.
- The Carbon Monoxide Detection with Better Sensitivity.
- There are four Screw holes for Easy Positioning
- With a long service life and reliable stability
- Rapid Response and Recovery Characteristics
Pinout

Pin No | Pin Name |
1 | VCC |
2 | GND |
3 | D0UT |
4 | AO |
Specifications
Product Dimensions | 32 x 20 x 22 mm (LxWxH) |
Operating voltage | DC 5 V. |
IC driver | LM 393. |
Size | 11 x 33 x 20 mm |
Range | 10 to 1000 ppm. |
Characteristic gas | 100 ppm CO. |
Sensitive resistance | 2 to 20 10kohm 10kohm at 100ppm CO |
Sensitivity | ≥ 3%. |
Return time | ≤ 30 s. |
Heating resistance | ± 31ohm 3ohm |
Heating current | ≤ 180 mA. |
Reaction time | ≤ 1 s. |
Heating voltage | 5.0V ± 2V / 1.5 ± 1V |
Heating power | approx. 350 mW |
Ambient temperature | -20 ° C to + 50 ° C. |
Humidity | ≤ 95% RH |
Oxygen content | 21%. |
Application
- Carbon monoxide (CO) detection: The MQ7 Gas Sensor is primarily used for detecting carbon monoxide gas. It is commonly employed in residential, commercial, and industrial settings to provide early warning and prevent carbon monoxide poisoning incidents.
- Indoor air quality monitoring: The module can be integrated into indoor air quality monitoring systems to measure carbon monoxide levels in enclosed spaces. It helps ensure a safe and healthy environment by detecting and alerting users to high levels of carbon monoxide, which can be emitted by faulty heating systems, fireplaces, or vehicles in garages.
- Automotive exhaust monitoring: The MQ7 sensor module can be utilized in automotive applications to monitor carbon monoxide emissions from vehicles. It enables the measurement of exhaust gases and facilitates the implementation of emission control strategies, ensuring compliance with environmental regulations and promoting cleaner air.
Datasheet
Download the Datasheet of the MQ7 Gas Sensor from the link given below.