The U.S. Department of Energy recently released a report on the initial performance and reliability of chromaticity sensors used for tunable LED lighting systems.
This study found that a chromaticity sensor used in the control system of a tunable lighting installation has high reliability, even under relatively harsh test conditions. The study examined the initial performance and aging characteristics of a sensor consisting of a series of six photodiodes that respond to different wavelengths to adjust illuminance, correlated color temperature (CCT), and chromaticity.
The sensor devices were exposed to a 5,000-hour accelerated stress test: one group at a continuous room temperature operating life, a second at a continuous but elevated ambient temperature of 75°C, and a third in a temperature-humidity environment of 75°C and 75% relative humidity (also known as a 7575 environment).
No abrupt failure of the sensor was found after 5,000 hours of testing, even in the relatively harsh 7575 environment. Just one parametric failure after 5,000 hours of 7575 testing was observed. Such a failure produces a change in a tunable device that would be noticeable to an observer. Light from the tunable fixture would likely be blue-shifted.
Related Stories
| Mar 30, 2012
CSI webinar: Durable & energy efficient building envelope design, April 24
This seminar will review recent changes in North America energy codes, examples of building enclosure wall assemblies being considered for code compliance, potential moisture management and durability challenges, and design tools that could be used to assess and minimize potential problems.
| Mar 30, 2012
Improved construction that followed seismic codes helped avert loss of life in Mexico temblor
A magnitude-7.4 earthquake that shook Mexico from Mexico City to Acapulco damaged hundreds of homes and sent thousands fleeing from swaying office buildings, yet no one was killed, according to early reports.
| Mar 30, 2012
Chicago may allow people to live in retail spaces
The Chicago City Council’s Zoning Committee approved a zoning change that will allow up to 50% of work space in low-intensity business districts to be used for living space.
| Mar 30, 2012
LEED growing fast in the housing rental market
Last year, developers of 23,000 U.S. multifamily housing units applied for LEED certification.
| Mar 30, 2012
Forest Stewardship Council critical of proposed LEED 2012 changes
According to the Forest Stewardship Council (FSC), the third draft of LEED 2012, if approved as written, would represent a step backward from the current Certified Wood Credit.
| Mar 22, 2012
Symposium on water efficiency: How much more water can be saved?
The Third International Emerging Technology Symposium by IAPMO and the World Plumbing Council features a session on water efficiency.
| Mar 22, 2012
Broker doesn’t have to inform contractor that insurer went broke, California court rules
A California appellate court ruled that an insurance broker did not have a duty to inform a subcontractor that a project’s insurer had gone bankrupt.
| Mar 22, 2012
Public agencies shouldn’t negotiate project labor agreements, says AGC official
When a public agency rather than the contractor negotiates a PLA with unions, it interferes with the right of employers and workers to reach their own agreements on working conditions and benefits, says Steve Isenhart, president of the Associated General Contractors of Washington.
| Mar 22, 2012
Proposed rule would let crane operators get licenses without prior city experience
The Bloomberg administration is considering letting operators of giant tower cranes get their license without requiring that they first run cranes as apprentices in the city for three years.
