In another post, I mentioned I was having issues with the dust collection from my jointer. I am at the point where I need to do some testing. I am using a magnehelic to monitor the resistance through the filters but I would like to also monitor velocity, cfm, and/or static pressure in the duct.

The dust collector is a Powermatic 075, 1900 cfm double bagger unit upgraded with 2 Wynn filters. The main duct is 8" from the dc inlet to an elbow then straight pipe to the last branch. Each branch is 7" and comes off the main horizontally before turning downwards. The branches run to blast gates where it then splits off to multiple inlets depending on the branch. I tried to maintain the same total duct area in the split inlets as the 7" branch duct, where possible.

Which type of probe would be best to use; pitot tube, hot wire anemometer, etc.?
When testing the system, do I have to probe each branch individually or can I just run a probe in the main duct to get "close enough" measurements?
If I test for velocity in the 8" main, can I use that data to calculate the cfm at the branch inlet if it is a different diameter?
Should I be concerned with measuring SP?

I don't think that I need it to be too terribly precise. I just want to be able to determine, roughly, how much air I am moving, how modifications to the system affect the airflow, and also when/if there is a blockage or other airflow issue.