Question: What tools or methods do you use to monitor odors?

If you can afford it, you can take air samples and then later inject them into a gas chromatograph/mass spectrometer (GC/MS). Couple that with a good data library and you should be able to ID most compounds.

Of course, you have to choose the right column, too.

I smell a sulphur kind of smell outside my house maybe 1x per month. I’d love to figure out what it is / monitor it.

There are plenty of ways to monitor it. Most importantly of them are expensive. The sulfur smell was probably hydrogen sulfide. There are some draeger tubes for testing it, but if it is only occassional, that's part of the problem. There are labs that will test also, again for a fee. One other option that I haven't heard much about in awhile is the copper test strip that public lab was working on. It would give a good long term coverage. Can anyone give an update on the copper strip hydrogen sulfide testing?

You can see a little more about the copper corrosion tests on the Methods Page for the Copper Pipe Method, (there are supplies to experiment with this method available in the Public Lab store)-- the copper pipe method is one that still has some open questions, so we'd love to see more people give it a shot in the field. You can also find a little more information about testing methods on the Hydrogen Sulphide Detection wiki, but I've also come across some cool info about H2S detecting in wine-making forums-- could be an interesting place to look for additional DIY methods.

Twitter user @RosaAriasAlv sent us this response to the Public Lab tweet:

For sure we are! We are developing an inclusive #citizenscience methodology in the framework of @dNOSES_EU to create collaborative #odour maps! You can try the free App @Odourcollect to map odours globally! A new version has been just launched for Android Odourcollect.eu

https://twitter.com/RosaAriasAlv/status/1096449234927263744