Building a cheap pitot tube for 20 CFM blower airflow

[jack1978]

Hi,

I have a small project where I run air from a blower into a hose with one elbow (or joint) in there. I am trying to calculate the static pressure and velocity pressure as well as the final pressure at the end of the circuit and would imagine I need to use a pitot tube to do this.

My fan is small and the hoses are 1" - 2" in diameter. The airflow from the fan is approx 20 CFM.

I have looked online at pitot tubes and have not seen anything less than $300 for this tool.

Surely there is a cheaper way to do this or a cheaper version of this tool that students might use. It is not something I will use professionally so therefore do not want to spend $300.

Any help with this is greatly appreciated.

Thanks,

Jack

 

[SteamKing]

Pitot tubes are not necessary to do what I think you want to do. Many flow set ups use simple water manometers to measure small changes in pressure, or mercury manometers if larger changes are anticipated.

 

[etudiant]

Agree entirely with SteamKing, a simple manometer is your best bet.
Just finding a pitot that would fit into a 1" diameter hose would be challenging and I'd be skeptical of the measurements, because it would distort the flow materially.
Separately, 20 CFM in a 1" diameter hose implies a vigorous flow. There will be heating effects.