DME (Design Margin Evaluation) is a qualitative reliability tool that measures the margin
between design strength of a unit and key environmental stressors such as ambient
temperature and incoming line voltage. Results can be used to improve the margin
of strength of a given design, as well as to highlight potential design weaknesses or
manufacturing aws.
Test methods such as HALT and DME are typically used as Reliability Growth Tests.
When used early in product design, engineers are able to identify potential failure
modes and then implement corrective actions or design changes to make the
product more robust. Life testing or ALT methods may then be applied as Reliability
Demonstration Tests to validate specied product reliability targets.
LEDs
Component-level qualication testing is performed on any new LED to validate
manufacturer claims and provide long-term reliability data under specified
conditions. Such reliability testing includes thermal shock, powered temperature
cycling and life testing under extreme temperature and humidity conditions.
Optics
The optics used in GE outdoor LED systems undergo a series of thermal soak,
thermal fatigue and water emersion testing to ensure material robustness, even
under elevated stress conditions. This provides condence across a broad range of
application conditions, including temperature excursions in the eld.
Mechanical enclosure
Fixture-level vibration testing is used to evaluate the mechanical reliability of the
system by simulating conditions that may be encountered during service. Examples
include vibration induced by trac, wind, ground disturbances, shipping and handling,
and accidental impact. Minimum testing of 100,000 cycles per axis for three axes is
designed to simulate normal fatigue conditions over the course of an outdoor
xture’s life, and is in line with ANSI C136.31. Additionally, enclosures undergo ingress
protection (per ANSI C136.25), salt fog testing (per ASTM B117 and D1654) and QUV
testing on the paint system (per ASTM G154 and D523). These accelerated tests are
designed to ensure durability under expected environmental conditions over the
product’s lifetime.
Figure 5: GE’s Evolve
™
LED Roadway
Scalable Cobrahead
(2 Seiten)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Kommentare zu diesen Handbüchern