This methane gas sensor detects the concentration of methane gas in the air and ouputs its reading as an analog voltage. The concentration sensing range of 300 ppm to 10,000 ppm is suitable for leak detection. For example, the sensor could detect if someone left a gas stove on but not lit. The sensor can operate at temperatures from -10 to 50°C and consumes less than 150 mA at 5 V. Please read the MQ4 datasheet (161k pdf) for more information about the sensor.
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 analog voltage on the other pins. A resistive load between the output pins and ground sets the sensitivity of the detector. Please note: that the picture in the datasheet for the top configuration is wrong. Both configurations have the same pinout consistent with the bottom configuration.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 20 kO.
We offer a Pololu breakout board that makes it easier to interface with these sensors.
This carrier board is designed to work with any of the MQ-series "gas sensors".
This semiconductor gas sensor detects the presence of combustible gas and smoke at concentrations from 300 to 10,000 ppm. The sensor's simple analog voltage interface requires only one analog input pin from your microcontroller.
Use these roll pins to fix sprockets to a shaft and keep them locked in place.
These large Tiller Traction Lug wheels are 13" in diameter. They come as pair and have steel 5/8" diameter shafts and bearings.