Air flow measurement - again...

[Mike Fahrion]

>   Just had a curious idea.  Im going to spit out every pro/con I can think
> of just to get the idea out of the table for discussion.
> 
>   Instead of using a MAF w/ its flow reversion problems, why not use a
> strain gauge?  Put a small object, like a sphere, in the airstream connected
> to an aerodynamic shaft to a strain gauge oriented to measure force in the
> direction of flow.  Should be able to read drag on the object quite
> precisely and quickly.  There could be non-linearities due to the shaft and
> object shape, but a look-up-table/linerization-circuit could correct these.

hmmm - won't the acceleration forces of the vehicle overshadow the 
useful data?  Even in a stationary application the vibration forces 
are fairly intense, although perhaps these could be filtered - this 
might reduce your bandwidth to an unacceptable level.

Just a (un-educated) thought.

-mike