Recalibrate Rotameters

Q_Goest

Science Advisor
Homework Helper
Gold Member
2,969
39
I have a rotameter for air measured in SCFM. I need to measure a helium flow rate.

I can't find a conversion on the net, but have come up with the actual flow rate in helium is equal to:

Q helium = Q air * (1/ Sg)^.5

Where Sg = specific gravity with respect to air
(Note: Helium Sg = 0.138)

So for example, if I'm measuring the flow of helium and the rotameter says 1 SCFM air, then I'm getting (1/.138)^.5 = 2.69 SCFM of helium.

Can anyone else confirm this or provide a different conversion?
 

The Physics Forums Way

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top