Re: Refrigerator monitor ideas?

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Robert L Bass" <no-sales-spam@bassburglaralarms> wrote in message
news:5NWdnexeNuFi5ljYnZ2dnUVZ_tSunZ2d@xxxxxxxxxxxxxx

> > How do they detect wing icing on airplanes?

<stuff snipped>

> There are three main types of sensors to detect wing ice --
magnetostrictive,
> electromagnetic, and ultrasonic.
>
> Magnetostrictive sensors use a vibrating coil.  As ice accumulates the
frequency
> of the vibration decreases, signaling the pilot and (in some systems)
automatically
> inflating the deicing boots.
>
> The space shuttle uses an electromagnetic device called a resonant
microstrip patch
> antenna.  There's an article on it at

 http://www.findarticles.com/p/articles/mi_qa3957/is_199905/ai_n8851736

Good information.  Thanks!  I wonder if I can buy spare space shuttle parts
on Ebay?

> > I do seem to recall that Palm 90 crashed
> > here a while back because the pilots
> > didn't know how badly iced they were at
> > the moment of takeoff...
>
> Wing ice is a major problem.  It can build up very fast when conditions
are right for it.
>
> > I believe someone used diluted deicer
> > that actually froze up on the wing surfaces.
>
> That is not what happened.

<stuff snipped>

While I agree it's not listed as the main cause of the accident, there's a
copy of the report at:

http://amelia.db.erau.edu/reports/ntsb/aar/AAR82-08.pdf

that supports what I said.  Since I was working in DC at the time of the
accident, we had a lot of local news coverage.  There was extended
discussion about whether the deicer was correctly diluted.  On page two of
the report (PDF page 7) the NTSB concluded that:

"The relief operator proceeded to deice the right side of the aircraft with
heated water followed by a finish anti-ice coat of 20 to 30 percent glycol
and 70 to 80
percent water, also heated. He based these proportions on information that
the ambient
temperature was 28F. (The actual temperature was 24 F.)"

I interpret that statement to mean the deicer the relief man applied was too
dilute for the actual air temperature.  I recall vividly the Potomac being
nearly frozen over, which means the plane had probably was even colder than
ambient, having cold soaked all night.  IIRC, it was a brutally cold snap
with temperatures in the single digits, which was very unusual for
Washington, DC.  There's page after page of detailed information about the
deicer composition, application and testing but I think if you miss the
freezing point you're screwed.

Anyone who's used standard windshield deicer in New England knows at a
certain temperature, you're just adding more slush to the windshield if
there's not enough alcohol in the mix.

> Someone I know claims to have snap-rolled a brand new 737 at low altitude
after having borrowed same from Boeing.  :^)

You just *know* that's going to generate flames.  Don't we have enough of
that crap?

)-:

--
Bobby G.