AP Research Measuring Methane Gas Concentrations


My name is Sabrina and I am an AP Research student from Washington State. My research evaluates the success of suspended soil substrate biofilters on the oxidation of methane from dairy farm effluent (cow manure mixture). For this research I will be measuring the methane gas levels and/or gas concentrations below and above the filter. I noticed there are methane and other gas sensors on this site I have some experience with soldering, programming in java and javascript, and have a Raspberry Pi. How difficult would it be to utilize these sensors? Is there a way to have them constantly monitor the levels and log the data in a spreadsheet? Could this handle 6 senors? My research needs to be completed by April 1 2020 at the latest. Any recommendations or assistance you can offer would be greatly appreciated.

Thank you!

You will need to state what sort of methane levels you are expecting to measure, what the contaminating gases might be, and the accuracy required for your project.

I recommend to consult a chemist at a nearby university for advice, and with that person’s help you may even be able to borrow or use suitable laboratory equipment.

Making accurate measurements of specific gases in the environment is neither easy nor cheap. Gas chromatography is typically used.

The inexpensive and readily available MQ sensors are totally unsuitable for quantitative measurements.

Hello, Sabrina.

I do not know what the needs are for your research, so I do not know if our gas sensors are appropriate. As Jim said, you will have to determine appropriate constraints and criteria for what your project needs, and consulting an expert would be prudent part of that. After you do that, you can look at the sensor datasheet (which you can find on product page under the resources tab) to see if they will work.

If you decide to set up a system that uses our gas sensors, then I think you can reasonably expect to be able to put something together comfortably within that time-line. However, you cannot use a Raspberry Pi easily to read these sensors since they output an analog voltage, and Raspberry Pis do not have a way to read analog inputs. Instead, you might consider using something like an Arduino or one of our A-Stars for that. The Arduino IDE supports C and C++ programming languages, not Java, but you do not need to do anything too complicated for this. There are also a ton of resources available you can use to figure out the programming.

The data logging will probably be the most difficult part of what you need to do. One option would be to output your data into a text file on an SD card that you could then read into a spreadsheet. There are Arduino expansion boards you could use for that, or you could use one of our microSD card breakouts (we have one that includes a 3.3V regulator and level shifters and one that is just a breakout). Alternatively, if you use one of our A-Star Primes, you could order a model with a built in microSD card reader.

- Patrick