SRC Forum - Message Replies
Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and Answers
Topic Posted by: Reliability & Maintainability Forum
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Posted by: Dwayne
Date posted: Tue Dec 11 10:10:07 US/Eastern 2001
Subject: reliability definition
Can anyone define the reliabilty for a light bulb that is going to be used outside?
Subject: Light Bulb Reliability
Reply Posted by: B.w.Dudley
Organization: Reliability Analysis Center
Date Posted: Thu Dec 20 14:54:36 US/Eastern 2001
Most light bulb from the manufacturer list the expected number of hours that the light bulb is expected to last given controlled conditions. These numbers vary from manufacturer to manufacturer, some have claims of lasting 10,000 hours or more. I would suggest that using the bulb in an outside environment, will reduce the expected life by a factor of at least two. Therefore, if the manufacturer lists 10,000 hours as the life, I would estimate 5,000 hours for the hostile outdoor environment. This estimate is based on the environmental factors published in MIL-HDBK-217, Reliability Prediction of Electronic Equipment.