Pressure Sensor for Flow Bench

[Steven Gorkowski]

Why are you using a variable speed motor when two manual bleeders ( mom
has a version on her vacuum )will do the job and only need AC motor. Im
spending my  money on the knife edge orifices .Unless you want to get
fancy with it. Just a suggestion I may have missed something.

Steve

garfield at pilgrimhouse.com wrote:

> On Fri, 8 May 1998 05:44:46 -0400 (EDT), Alain Toussaint
> <alaint at boisfrancs.qc.ca> wrote:
>
> >> BUT,
> >> just about all the blower motors all them FlowBench guys use now
> are
> >> AC/DC motors that can be easily thyristor controlled
> >
> >i think a word must be said about efficiency of the fan used there
>
> But, but , but it's already being done. This is how all the Quadrant
> Scientific flow benches work, already. Since you are controlling the
> motors in closed-loop, with diff. pressure drop across the DUT as your
>
> set point, as long as the blower motors don't LARGELY go to pot, you
> don't really care if the efficiency isn't completely constant over the
>
> range you're varying the rpm. The other thing to observe is that these
>
> blower-motors aren't like single stage rotary or squirrel-cage fans;
> they're actually more like lil 2-stage turbines inside.
>
> Maybe it's like EGOR and ION, they may seem like hard problems if we
> were approaching them for the first time, and starting from first
> principles, but an existence proof is worth a ton of speculation, and
> once there's proof that it's been done, and that cheaply and
> practically, then we can dispense with worrying about the "order" of
> certain effects and issues, and just go DO IT. Thas eXactly why I
> mentioned the Quadrant Sci stuff.
>
> Not tryna say that the issue of blower efficiency isn't REAL, just
> that
> given commercial implementations built around varying the blowers
> under
> thyristor control, it just can't be a show-stopper. Unless them guys
> use
> a special sauce the recipe for which is currently a trade secret, ala
> Kernel Sanders. [BTW, I don't ever recall hearing of anyone
> successfully
> reverse-engineering his chicken, have you? Now THERE'S an example of
> an
> effective and well kept trade secret. Whew! Humbling, idn't it?; to
> think that what stuff we're doing here is easier than tryna duplicate
> someone's cooking yer fond of. Heh].
>
> Garfield
> (confirmed birdatarian; if you know the Kernel's recipe', lemme know!
> I
> gotta great zuccini-bread recipe' I'll trade ya. B)