Best air flow measurement method?

[CnoJ]

Hi,
I often need to know mass flow rate through air cooled industrial equipment and usually struggle to get repeatable measurements using vane or hot wire anemometers. I can only measure at the intakes, which are up to 700mm (~28") sq with flow in the 1500 to 5000 CFM range. Fan pressure is usually around 200-300Pa.
What methods or equipment are most accurate for measurements like this? Set-up time and cost aren't big concerns as much as getting measurements with a known accuracy (is 5% asking too much?).
All suggestions/comments appreciated.
Thanks,
Jon C

 

[willard3]

Have you tried an air balancing hood?

https://www.testo.com/en-US/testo-420/p/0563-4200

 

[CnoJ]

I haven't found a hood that will cover my CFM range, they seem to stop around 2500 CFM.
Would a pitot grid be my next best option? Is there such a thing as a hot wire anemometer grid?

 

[itsmoked]

The company I used to work for helped Kurz Instruments with a plethora of mass-flow instruments for measuring all kinds of flows. Even the mass-flow thru Moss Landing's stacks that are about a hundred feet across.

[URL unfurl="true"]http://kurzinstruments.com[/url]



Keith Cress
kcress -

http://www.flaminsystems.com