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Electricity/Measuring

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Vitali
164878.  Wed Apr 11, 2007 9:59 am Reply with quote

In the early 20th century, electricity was at times measured in "candle-power", just like engine capacity - in horse power:

"The dioptric apparatus is supplied with an incadescent petroleum burner, and the brass is a five-second flashlight, with a 750,000 candle-power. "
/from description of the Sherkin Lighthouse in "Murray's Ireland, 1912"/

 
eggshaped
164900.  Wed Apr 11, 2007 10:27 am Reply with quote

I think it's the intensity of light which is measured in candles isn't it? Rather than electricity as such. It's like saying that electricity is measured in mph because it can be used to power a car.

IIRC, the standard unit of measurement for light-intensity is a candella which I presume originally comes from candle-power.

 
Gray
164917.  Wed Apr 11, 2007 10:44 am Reply with quote

eggshaped is quite right - candle-power (or candela) is a measure of light intensity.

Quote:
Prior to 1948, there existed a variety of standards for luminous intensity in use in various countries. These were typically based on the brightness of the flame from a "standard candle" of defined composition, or the brightness of an incandescent filament of specific design. One of the best-known of these standards was the candlepower.


http://en.wikipedia.org/wiki/Candela

 
MatC
164931.  Wed Apr 11, 2007 11:07 am Reply with quote

I think they still use candle power for torches, etc. As
here

I just pity the poor bloke who had to count 10,000,000 candles.

 
Gray
165012.  Wed Apr 11, 2007 5:06 pm Reply with quote

No tenebrous elucubration for owners of that baby.

 
Jenny
165021.  Wed Apr 11, 2007 6:31 pm Reply with quote

Architects call it 'foot candles', meaning the amount of light from a standard candle that you can measure one foot from the candle.

Source - my old man, the architect.

 
Flash
165023.  Wed Apr 11, 2007 6:44 pm Reply with quote

The SI equivalent of the foot candle is the lux. But I think foot candles have a place in the notes alongside the ear candles at minimum. I'll post a link there.

 
Vitali
165286.  Thu Apr 12, 2007 9:41 am Reply with quote

Eggshaped is right: it is the intesity of light, of course... Sorry, my mistake...

 

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