A low-cost DIY methane sensor for Team Braunschweig

Our colleagues from Braunschweig are cultivating microorganisms that grow on methane (CH₄) which is supplied via the gas phase. To monitor the methane uptake by their E. co(w)li, they would like to measure the methane concentration in the gas phase. With the standard analytical methods in the lab, this is very difficult, but when they told us about their problem, we knew that we might be able to help them. We assembled an Arduino-based methane sensor and wrote a program to record the data.

The componentes for the methane sensor include:

• [http://www.dx.com/p/arduino-nano-v3-0-81877 Arduino Nano V3 clone]
• [http://www.sainsmart.com/sainsmart-mq-4-methane-gas-sensor-natural-coal-co-detector-module-for-arduino.html SainSmart MQ-4 Gas Sensor]
• A [http://www.dx.com/p/syb-170-mini-breadboard-for-diy-project-red-140101#.U-ng9VLwC7Q Breadboard] and some wires

To set up the electronics for a measurement, the sensor and the Arduino have to be connected according to the following scheme:

Connecting the MQ-4 module to the Arduino Only three wires are required to connect the MQ-4 module to the Arduino Nano.

We sent all the components to Braunschweig and they assembled the Arduino and sensor module in an incubation chamer:

MQ-4 sensor in the gas phase For anaerobic cultivation, a wireless connection might be better.	Online data on a laptop The Arduino is connected to a laptop running our Serial Client software to plot and collect online data.

The software used to monitor the online methane concentration data is the Serial Client that was also developed by our team.