# Cheaper Pitot tubes?

1. Mar 27, 2014

### 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

2. Mar 27, 2014

### SteamKing

Staff Emeritus
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.

3. Mar 27, 2014

### 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.