One could think of an object here on Earth as an antenna receiving energy
from the sun. Since the sun is transmitting about 4 × 10**26 watts, it is
not difficult to understand why that Al plate got so hot.
The reason a white object does not get as hot as a dark one is simply that
it reflects a large portion of light energy instead of absorbing it. Also,
an object with more mass stores more energy. Translated into desired
properties of fiberglass used as guy lines: white, thin rod with high
temperature resistance.
73, Keith NM5G
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Roger K8RI on Tower
Sent: Monday, May 02, 2005 10:35 PM
To: Tom Rauch; k3mm@comcast.net; towertalk@contesting.com
Subject: Re: [TowerTalk] polyrod
Just as a point of interest on color and heat.
In a glass covered solar heater using Forest Green as the color on the
heating element, if the water flow stops, I believe the resting temperature
of the element will be around 340 to 380 F.
I've seen bare aluminum plate 4' X 8' X 1" think (that's heavy!) that had
been left laying on the pavement in front of the shop where I used to work
get so hot that a cup of water thrown on it would hiss as it turned into
steam. It was like throwing water onto a hot frying pan.
Roger Halstead (K8RI and ARRL 40 year Life Member) N833R - World's oldest
Debonair CD-2 www.rogerhalstead.com
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
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