RadioBanter - View Single Post

July 21st 05, 06:45 PM

On Thu, 21 Jul 2005 09:47:12 -0500, (Richard
Harrison) wrote:

Richard Clark wrote:
"Actually that is quite wrong. IR is not heat."

He got me. According to Lincoln`s Industrial Reference, from a 100-watt
MAZDA lamp the amount of energy emanating as light is 10%, and as
infrared is 72%. The rest is lost to gas end loss, etc. The loss would
be only 18% You can`t see infrared. The eye is most sensitive to a
yellow-green color around 5550 Angstrom units. Lamps are made to
emphasize white or "daylight" which is rated at about 2400 to 3100
degrees Kelvin.

Hi Richard,

Well, your ability to research the topic continues well in advance of
other's effort. Some may note the congruence of the specified
emission peak and my statements earlier choosing exactly this same
wavelength. This is called the eye's photopic response, but at night
it shifts slightly to become more sensitive in its scotopic response.
This is rod vision and occurs around the 510nM (5100Å) wavelength or a
pale blue.

The unintended consequence of this is that it suppress the eye's
ability to perceive red light at night (why you see them used in dark
rooms and WWII movies) which is something of a bummer for traffic
lights and taillights (they have to be brighter than they would be
normally).

Also, this discussion bears upon the answer to
"What is the wavelength of Glare?"
that has remained undiscovered by binary engineers. I bet our Readers
can catch this clue. :-)

73's
Richard Clark, KB7QHC