Air Purifier

My parents recently bought me an air purifier in hopes that it would alleviate the ridiculousness that is my nose; and it actually seems to be working! The best feature of this air purifier is that it has a small screen on the top that displays the "Particle" level, "Smell" level, as well as speed of the fan inside the air purifier. As it should work, if the particle level or smell level increases above normal, the fan kicks to a higher gear to deal with the unclean environment. I didn't think much of it until my neighbor was mowing the lawn and my purifier suddenly revved into a higher speed. I closed the window and within minutes the lawn cutting smell was gone from my room. Impressive, I thought. I didn't really know how sensitive it was until today when I passed some gas [read: farted] four feet away from the thing, and moments later I heard it whirrling faster to deal with my release. Very impressive.