Denver Chapter
Dr. Sam Keene, FIEEE, Chair

CALT and CALT- MEOST
Correlated Accelerated Life Testing With Combined Stresses

Correlated accelerated life tests are a key enabler when one needs to demonstrate a high degree of reliability and do so in the shortest possible time.  Correlated tests provide the critical acceleration factor relating how long a device lives on test to how long that device will live in the field.  The Calibrated Accelerated Life Test method (CALT) is experiencing a growing following in many industries and countries around the world.  Its effectiveness has been proven in both for mechanical devices as well as electrical products.  A follow-on to CALT is CALT- MEOST (Mixed Environment Overstress Testing), where we combine different stresses that work together to produce a common failure in anticipation of taking advantage of interactions and synergistic effects.  We are able to retain correlation to the field using the CALT- MEOST method, and with as few as 6 test samples, can evaluate the combined effects of an unlimited number of stresses.  Yes you read that correctly and that was not a misprint.  This method is now being used in a wide range of industries including the wind turbine industry.  The 45 minute presentation by Larry Edson covered both of these methods showing applications in the wind turbine industry.