Thanks Chris! I looked briefly and it does look like there are several threads out there addressing my hunt for a low cost and fairly accurate method for measuring flows and pressures. Pitots and manometers seem popular. I did see a link to a Wood magazine article. I wasn’t crazy about all their methods but it appeared better than most (
https://www.woodmagazine.com/video/dust-collector-test).
I understand the science and have practical experience in the measurements and analysis. This is why seeing those prop anemometers used makes me cringe!
It’s been a while now (around 20 years ago now) but I spent about 5+ years doing measurement and analysis for nuclear plants to determine their capability of removing heat load during accident scenarios. It involved many measurements of their systems including air flows for heat exchangers and such. I had to also determine all measurement uncertainties and project those to accident conditions. The plants must have enough capacity including the extrapolated uncertainties to remove accident scenario heat loads to prevent meltdown. I’ve even authored a text and taught a class for the nuclear industry sponsored by EPRI on the measurement and analysis so the plants could maintain a program to measure and verify they met the NRC requirements.
While I have knowledge and experience in that area, I haven’t measured a small system such as my dust collector. So these forums and info are very helpful. Heck This weekend is the first time I did the math and I was quite surprised with the results. You know what assuming does!
Obviously, when I did such measurements professionally we had some of the best instrumentation and all very well calibrated and maintained. I have been pleasantly surprised with some cheap instrumentation from Amazon and such sources. But I also know most aren’t remotely what the claims say.
I will add those vane/prop anemometers stuck on an open duct with who knows what flow sections prior to it are useful in proving one’s theory. I mean you could pretty much get that to read anything you wanted it to ;-)