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Posted:
Wed Nov 09, 2005 12:35 amby Mouse
If you are using a single port Pitot tube in a 3" pipe, you are not getting an average velocity reading, but rather only the velocity at the point of measurment. You need to take several readings across the diameter and average them into one velocity reading.
If you are using a multi port averaging Pitot tube, then you need to adjust your area factor to fit your desired readings.
Or, if you multiply your readings by .65 as a correction factor, you will get pretty close to your desired results.
John
Posted:
Wed Nov 09, 2005 8:53 amby wing64k
Thanks John,That helps a lot,how did you come up with the correction factor,that really get me close to my calibration plates..If I decide to go with the FP1 system will it work with my pitot style bench?I have a set of ALL-PRO heads that I had on a SF-600 last week,I will test tonight and see how this works out now.
Thanks,Dean
Posted:
Wed Nov 09, 2005 10:55 amby Mouse
Dean,
I got your correction factor by trial and error on one set of numbers, and luck has it it fit the others too. But that was to be expected if your bench is working correctly. Just keep tweaking it up or down until all ranges fit best.
You can eliminate the correction factor by just adjusting your area factor to fit. Just keep tweaking it up or down until all your flow figures are within, or as close to, 1% as possible. Pitot tubes rock, don't they!
You bet the FP1 will work on your bench, in fact, it was originally designed around Pitot tube setups. Should only take you 5 minutes to be up and running once you have one in your hands.
If you want to reduce your 5 foot flow element to about 24", our FE3.0m flow element will do the trick for you too.
John
Posted:
Wed Nov 09, 2005 1:09 pmby wing64k
Thanks John,The light bulb just got brighter,now I understand what I got to do..I will make the adjustments and run a test tonight,I will be changing to the FP1 soon.
Dean