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Changes
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→LED
LEDs have a long life (100,000 hours) and low heat output. They give off a soft natural light in white, red, green or blue. White or blue are used for reading, e.g., a reading spot lamp. Red, green or blue are used for night vision.
In a low voltage DC system, their driving system is simple and cheap compared to a fluorescent, which requires an oscillating ballast circuit. LEDs use a simple voltage-dropping resistor. They are tough and resistant to shock and vibration. They are safe near explosive gases and liquids. In a marine installation, use a dual-pin ungrounded LED. Until recently LEDs were rated in millicandela (mcd), as measured at the light source, not lumens. This made direct comparisons with other light types fuzzy. (One lumen is approximately 79.5 mcd [7].)
Now that LEDs are more competitive, manufacturers are also rating them in lumens.