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
| Nov 3, 2011
OSHA Publishes Information on Rights and Safety
OSHA recently published new and revised information that explains workers’ and employers’ rights, as well as how to protect workers from hazards in the construction industry.
| Nov 3, 2011
Sierra Club Critical of Albuquerque Mayor’s Push to Weaken Green Code
The mayor’s plan to move to a less environmentally friendly code would mean confusion for people in the construction industry and a loss of energy efficiency and money for consumers, said Shrayas Jatkar of the Sierra Club.
| Nov 3, 2011
Lax Code Enforcement Blamed for Deaths in Turkey’s Earthquake
Despite tough safety codes approved a decade ago after earthquakes killed 18,000 people, lax enforcement led to hundreds of deaths after a recent earthquake in Turkey.
| Nov 3, 2011
International Green Construction Code Will Provide Template for Local Codes
A uniform code for green construction is being readied for publication in March.
| Oct 31, 2011
NIST issues new code requirements
Buildings taller than 420 feet are now required to include an extra exit stairwell or a specially designed elevator that occupants can use for evacuations.
| Oct 28, 2011
Los Angeles County mulling building codes for improving health
An ordinance would amend county building codes to promote better walking environments, encourage more bicycling, improve access to healthy foods (farmers markets, community gardens), and enhance project review requirements to ensure that developers include healthy-lifestyle components in their building plans.
| Oct 28, 2011
Bipartisan opposition to federal 3% withholding for contractors
Both major political parties and the Obama Administration support repealing a law that would withhold 3% of all government contracts.
| Oct 28, 2011
OSHA requires training module on top causes of construction deaths
The Occupational Health and Safety Administration (OSHA) now requires a training module on the top four causes of death for construction workers.
| Oct 28, 2011
New York City requiring building energy use to be posted online
Owners of every New York City commercial and residential building larger than 50,000 sf will have to post each building’s energy use online by 2013.
| Oct 28, 2011
New ISO standard for escalator safety
A new ISO standard specifies safety requirements for escalators and moving walks.