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Research and Radionavigation

Forum to discuss all areas of lighthouse technology such as optics, fuels, fog signals, radiobeacons, daymarks, construction, etc.

Postby Fred » Thu Jul 23, 2009 3:34 am


For those interested in the way things are going?

General Lighthouse Authorities' Research and Radionavigation Directorate (R&RNAV) has just launched its new web site at http://www.gla-rrnav.org.
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Postby CHUCKX53 » Thu Jul 23, 2009 12:28 pm


Thanks for posting that link to a very Interesting site, Fred....Much appreciated... :!:
LIVE LONG AND PROSPER
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Postby Fred » Thu Jul 23, 2009 3:42 pm


I like the part from the site about candlepower then and now.

"The original definition of a 'standard candle' was:

"A 7/8 inch diameter sperm whale fat candle weighing one-sixth of a pound, burning at the rate of 120 grains per hour."

The modern definition of the candela is:

"the luminous intensity in a given direction of a source that emits monochromatic radiation of frequency 540 x 1012 Hz and that has a radiant intensity in that direction of 1/683 watts per steradian""

Then goes on to five different ways of measuring effective intensity,no wonder us lightkeepers used to get confused,at least using paraffin lights you had a glimmer of an idea what candlepower was when asked how many candlepower is the light?
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Postby Lighthouselin » Fri Jul 24, 2009 7:01 am


Fred that is a really interesting site. Thank you for posting it, I will be reading so much on it. :)
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