Forwarded: Re: Airflow measurement - again...

[RABBITT_Andrew at mv8.orbeng.com.au]

LDA requires particles in the air-stream to work.  Fortunately the 
dust present is enough.  The system works by intersecting two laser 
beams at the point you want to measure the velocity.  At the 
intersection, the two beams form interference bands.  As particles 
travel through the intersection, they reflect pulses of light at each 
constructive interference fringe.  A photo-detector senses this 
reflected light.  The frequency of the detected pulses is directly 
related to the speed of the particle, which is related to the flow 
velocity.  Note though that this is not a MASS flow detector

Andrew Rabbitt  

From: (Mazda Ebrahimi) kleenair at ix.netcom.com:smtp
Date: ## 12/20/96 22:34 ##
RABBITT_Andrew at mv8.orbeng.com.au wrote:
> 
> What I'd be interested in is a LDA (laser-doppler-anemometery) type
> air velocity sensor.
> 
> Andrew Rabbitt

Andrew,

I've been away for a few days and have alot of messages to read ....
Can you explain LDA further?

Best Regards, Mazda