Average Rated Life (ARL) of Light Bulb

Average Rated Life (ARL)

Working periods of half of the light bulb of a batch is known as Average Rated Life (ARL) of light bulb. Some times it is called a half – life. It can easily explain in this way; if 1000 bulbs are tested and 500 of its can reached 1000 hours, the Average Rated Life (ARL) is 1000 hours. Some bulbs can light for 100 hours; some are 500 hours, some within 650 hours. But ARL is that period, which half of the light bulb working.

Frequently on and off switches of light bulb reduced the ARL. This is less affected for Incandescent, halogen, and LED bulbs. Fluorescent, Compact Fluorescent (CFL), and HID bulbs are more affected by on/off cycles. Main thing is ARL of a light bulb is longer for once or twice turns on/off than many times turns on/off in a day.



A preferable condition is select in typical applications for testing the ARL. There are some effects in ARL for the condition of using place of light bulb. If a light bulb is used in an area that is cold (in a freezer or outdoor in winter), hot place, wet (uncovered in rain) or vibrating (near generator or other machinery) or any abnormal condition places; most of the time ARL will not be reached.


Typical Average Rated Life (ARL) for Various Types of Bulbs

Bulb	ARL
Incandescent	750 - 2,000 hours
Fluorescent	24,000 - 36,000 hours
HID	10,000 - 24,000 hours
Compact Fluorescent Plug-in Screw-based	10,000 - 20,000 hours 8,000 - 10,000 hours
Halogen	2,000 - 4,000 hours
LED	40,000 - 50,000 hours