I've had the Dylos Pro for years. I haven't been making dust lately but turned it on to check it and the count was about 300. Like Alan, I also use a 5hp cyclone which really helps according to the Dylos. I don't have my air cleaner up now but in the past I have watched the numbers go back down to normal over the course of an hour or so. I also use the 3M half mask respirators when making sawdust.

There was a thread here not long ago about some very low-cost air quality monitors available, I think, from eBay. Maybe search, or someone may have the info.

JKJ