Carbon Monoxide CO Sensor Module MQ-7

The MQ-7 sensor module is required to detect carbon monoxide in the environment. It is also able to detect such gases as propane, propylene, butane and natural gas. Sensor readings are taken in the range of 10 - 1000 ppm.

Module designed on MQ-7 gas analyzer and LM393 comparator. The comparator converts the received electrical impulse from the sensor into a digital or analog signal. The gas analyzer consists of a mesh made of stainless steel, inside of which there is a ceramic tube. A heating element is placed in the body of the tube, which heats up with a large amount of harmful substances.

A potentiometer is used to change the sensor threshold.

There are also 2 LEDs on the board, where PWR-Led signals that voltage is applied to the sensor board, and D0-Led lights up when the gas analyzer signal reaches a high level.

4 pins are used to connect the board. Power connections are made through the VCC and GND pins, and analog and digital signal transmission is made using the A0 and D0 pins.

The module can be powered by an Arduino board or other microcontroller device and an external 5V power supply.

Sensor Specifications:

Supply voltage, V 2.5 ... 5
Sensor MQ-7
Power consumption, mW 350
Gas concentration detection, ppm 10 ... 1000
Warm-up time, s 60
Operating temperature, °C -10 ... +50
Module dimensions, mm 35 × 20 × 11

Scheme for connecting the sensor to the Arduino Uno: