The values calculated here are differences from the average of the first 2o samples. The X axis is time, but it’s not well-specified because I didn’t actually set a regular timer, I just collected samples as fast as possible.

As was predicted in the previous entry, the MQ-135 and MQ-3, both of which can sense alcohol, had the strongest response to vape clouds. These are the ones I’d use for the primary detection if I was building a serious vape detecting product.

The MQ-9 and MQ-8 had similar responses, but not as strong. This is kind of interesting, since they are supposed to be good for butane, propane, LPG, and hydrogen, but maybe they just do a decent job detecting light molecules with carbon in them? The MQ-2 response is interesting, since it’s sold as a LPG, propane, and hydrogen detector, but has a moderate response to vapes too.

The much lower results seems to indicate that vape clouds have no VOCs (CJMCU-1100) and no town gas or LPG (MQ-5, but I didn’t need a sensor to tell me that).