Calibrate Rotameters for Helium Flow Rate

  • Thread starter Thread starter Q_Goest
  • Start date Start date
Click For Summary
SUMMARY

The calibration of rotameters for measuring helium flow rates can be accurately determined using the formula Q helium = Q air * (1/ Sg)^0.5, where Sg represents the specific gravity of helium with respect to air, specifically 0.138. For instance, a reading of 1 SCFM of air translates to approximately 2.69 SCFM of helium. This conversion method is essential for ensuring accurate flow measurements when using rotameters originally designed for air.

PREREQUISITES
  • Understanding of rotameter operation and measurement principles
  • Knowledge of specific gravity and its implications in fluid dynamics
  • Familiarity with standard cubic feet per minute (SCFM) as a flow measurement unit
  • Basic mathematical skills for applying conversion formulas
NEXT STEPS
  • Research the properties of helium, including its specific gravity and flow characteristics
  • Learn about the calibration process for rotameters in different gas applications
  • Explore advanced flow measurement techniques for gases
  • Investigate the impact of temperature and pressure on gas flow rates
USEFUL FOR

This discussion is beneficial for engineers, technicians, and researchers involved in gas flow measurement, particularly those working with rotameters and requiring accurate conversions for helium flow rates.

Q_Goest
Science Advisor
Messages
3,013
Reaction score
42
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?
 
Engineering news on Phys.org

Similar threads

Volumetric flow rate of nitrogen through relieving pressure regulator
  • · Replies 3 ·
Replies
3
Views
3K
Flow Calculations: Solenoid & SLM Rates
  • · Replies 3 ·
Replies
3
Views
5K
Understanding Backpressure Effects on Flow Meter Calibration
  • · Replies 10 ·
Replies
10
Views
3K
Steps to calculate Air Consumption of a Pneumatic System
  • · Replies 6 ·
Replies
6
Views
18K
Flow rate of air in discharging reservoir
  • · Replies 1 ·
Replies
1
Views
2K
Gases at Sonic Velocity - Choked Flow
  • · Replies 3 ·
Replies
3
Views
6K
Underground pump vault airflow considerations
  • · Replies 15 ·
Replies
15
Views
4K
Undergrad Finding flow rates for different gases
  • · Replies 2 ·
Replies
2
Views
15K
Discover How to Measure Flowrate Through Varying Tube Diameters
  • · Replies 1 ·
Replies
1
Views
2K
Calculation of water flow rate in heat exchanger
  • · Replies 6 ·
Replies
6
Views
14K