Measuring Air Flow

[servant74]

Does someone have a quick/cheap way to measure air-flow, like in feet per second or feet per minute?  Preferably something that doesn't have to be calibrated.

In a perfect world, I would love to have a cheap 'attachment' I could hook onto or put in-line to a duct that would measure the flow rate.

Years ago (high school, back when dinosaurs roamed...) I built a wind tunnel.  And my Dad got the specs to build a pitot/static tube that I used in a science project.  It measured in inches of water the pressure differential.  I just don't remember the specs to re-build it.

TIA ... Jack

[phil (admin)]

For relative measurements (just making comparisons before/after changes, for example), I use a weather vane anemometer.  I used a Kestrel (supposed to calibration test back to NIST):

http://www.nkhome.com/ww/1000.html

When I need to be precise, I can borrow gear from a friend that works in HVAC.