MQ-7 CO Carbon Monoxide Coal Gas Sensor Module

The MQ-7 CO Carbon Monoxide coal gas sensor module detects carbon monoxide (CO) in the air. It pairs the MQ-7 sensing element with a comparator board, so you get an analog output that rises with CO concentration and a digital output that switches at a threshold you set with the on-board potentiometer. It connects directly to an Arduino, ESP32 or other microcontroller for CO monitoring and warning projects.

MQ-7 CO Carbon Monoxide Sensor Specifications

• Sensor: MQ-7 tin dioxide (SnO2) semiconductor gas sensor
• Target gas: carbon monoxide (CO), with some cross-sensitivity to hydrogen
• Detection range: 20–2000 ppm CO
• Heater (datasheet): 5 V for 60 s and 1.4 V for 90 s for CO measurement
• Supply voltage: 5 V
• Outputs: AO (analog voltage) and DO (digital, threshold set by the potentiometer)
• Pins: VCC, GND, DO and AO

MQ-7 CO Carbon Monoxide Sensor Applications

• CO warning projects near heaters, generators and fireplaces
• Monitoring garages and workshops for exhaust fumes
• IoT air monitoring with ESP32 or ESP8266
• Gas sensing experiments in STEM and university labs

What's in the Box

• 1 × MQ-7 carbon monoxide gas sensor module

Tip: Most modules run the heater at a constant 5 V, so treat the readings as a relative indication; for calibrated CO measurement follow the datasheet's 5 V / 1.4 V heater cycle. Let a new sensor run for about 48 hours before calibrating it, and never use it in place of a certified CO alarm.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.