Venturi Vacuum
Venturi Vacuum
(OP)
I have an application where I want to confirm air-flow in an extraction duct. At present we use a diaphragm type vacuum switch which measures the vacuum from a smaller L-shaped pipe fixed in the middle of the air flow, i.e the venturi principle.
The vacuum switch is unreliable. I have measured the vacuum at 55mm water. This with a simple water tube. This equates to 5.5 milibar (if my calculations are correct).
The range on the vac switch is 5~50 milibar.
My question is how can I increase the vacuum to bring it closer to the switch mid-range?
Would a funnel type opening on the end of the venturi pipe help?
Regards,
Speedy
![[roll1] roll1](https://www.tipmaster.com/images/roll1.gif)
![[roll1] roll1](https://www.tipmaster.com/images/roll1.gif)
The vacuum switch is unreliable. I have measured the vacuum at 55mm water. This with a simple water tube. This equates to 5.5 milibar (if my calculations are correct).
The range on the vac switch is 5~50 milibar.
My question is how can I increase the vacuum to bring it closer to the switch mid-range?
Would a funnel type opening on the end of the venturi pipe help?
Regards,
Speedy
![[roll1] roll1](https://www.tipmaster.com/images/roll1.gif)
![[roll1] roll1](https://www.tipmaster.com/images/roll1.gif)





RE: Venturi Vacuum
Look at:
http://ww
If you reduce the diameter at the throat, you'll decrease the pressure more (better vacuum).
RE: Venturi Vacuum
RE: Venturi Vacuum
If you simply need to know flow or no flow, a sail switch might be a better choice.
RE: Venturi Vacuum
To clarify - it is in fact a pitot tube, with no static pressure measurement. It's function is to clarify FLOW / No FLOW.
I like the idea of a sail switch, but I have to find one with ATEX approval.
Any suggestions,
Speedy