Air flow meter

[hawkeye177]

Does anybody know where I can buy or build a AIR flow meter.

Socalgal please move my topic if I am not in the right forum. New layout.

[Dove19983]

Building a air flow indicator (http://www.ocmod.com/code/show_art.php?id=21&pg=1) . I think this is what you want.

[hawkeye177]

No, that is a water flow meter. I need something to figure out the cfm of the fans

[thekingofpain]

Not sure if itl help but I use a handheld device for measuring windspeed (I fly stuntkites) measures down to .07 mph---maybe you could figure a way to convert it somehow into a useful cfm measurement---cost about 20$ at my local kitestore...

[This message has been edited by thekingofpain (edited 06-11-2001).]

[hawkeye177]

I found one but it is $$$$2000.00. I cant afford this thingy. Can anybody help http://www.dwyer-inst.com/htdocs/flow/APM151.html

[hawkeye177]

Ok it does not work. I think it is because it has been siting on my garage floor for 2 years.
Sysopt please tell me more on how to make it.

[hawkeye177]

please help me

[hawkeye177]

I am going to buy a cheap speedometer for the air flow thing.

[SysOpt]

I built one for a science project years ago. All you need is a DC fan (like the ones used to cool computers), a digital counter, and a funnel/tunnel (I used air conditioning ducts and adapters to downsize the tube to the width of the fan housing.)

I mounted a small magnet on the fan, and a magnetic sensor on the fan housing. As air passed through the fan, the magnet went around each rotation past the sensor. The sensor was connected to a digital counter (that I built but you can buy for <$15). So, in any given period of time, you can count the revolutions - the more revolutions in a given period of time, the higher the airflow. You could calibrate the unit by using airflows of known rates. The project was: How does propeller pitch affect airflow?

I got 4 first place ribbons at the regional science fair and $350 total from NASA, the American Vacuum Society, and the Society of Mechanical Engineers, so it works http://www.sysopt.com/forum/wink.gif.

[This message has been edited by SysOpt (edited 06-11-2001).]

[hawkeye177]

Thanks for the idea. I can use a little sensor that measures the speed you are going on a bike. I know I have one of those. That would work because the sensor picks up the magnet going through it. You can calibrate by making a formula using a known cfm fan and seeing how many revolutions it makes. Thanks again sysopt
I am going to try to get the parts as soon as I log off.
I will give you my results.