Carbon Monoxide Gas Sensor MQ-7

This semiconductor petrol sensor detects the presence of Carbon Monoxide at concentrations from 10 to 10,000 ppm. The sensor’s simple analogue voltage interface requires only one analogue input pin from your microcontroller.

Not currently available

Our Code: SKU-002624

Supplier Link: [Pololu MPN:1482]


Description

Gas sensor with orange plastic case with quarter for size reference

Overview

This Carbon Monoxide (CO) petrol sensor detects the concentrations of CO in the air and ouputs its reading as an analogue 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 5 V. Please read the MQ7 datasheet (185k pdf) for more information about the sensor.

Gas sensor with orange plastic case bottom view

Connections

Connecting five volts across the heating (H) pins keeps the sensor hot enough to function correctly. Connecting five volts at either the A or B pins causes the sensor to emit an analogue voltage on the other pins. A resistive load between the output pins and ground sets the sensitivity of the detector. The resistive load should be calibrated for your particular application using the equations in the datasheet, but a good starting value for the resistor is 10 kΩ.

We offer two breakout boards that make it easier to interface with these sensors: a Pololu carrier board and a SparkFun carrier board. The Pololu version is shown below.

Pololu MQ gas sensor carrier with sensitivity-setting resistor soldered in the vertical orientation


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