The U.S. Department of Energy (DOE) will be changing LED bulb energy efficiency tests, according to a report from Chinese media Xinhua.net.

According to a source from Zhejiang Entry-Exit Inspection and Quarantine Bureau, the DOE latest proposal issued in late June 2014 involves defined methods for measuring lumen output, input power, and relative spectral distribution (to Determine correlated color temperature, or CCT). Changes were also made to LED lamp lifetime calculation methods that will be defined as the time required for the LED lamp to reach a lumen maintenance of 70 percent.

In a recent supplemental proposed notice issued by DOE, the definition of “lifetime” was changed. DOE proposed revising the name of “lifetime,” to “lifetime of integrated light-emitting diode lamps.” Under the new proposed definition, the lifetime of integrated LED lamps is “the length of operating time between first use and failure of 50 percent of the sample units (as defined in § 429.56(a)(1)(i))...”

Definition of time to failure was also redefined to support the new lifetime definition. Under the new definition, the time to failure will be determined as when a LED lamp reaches luminous maintenance level of 70 percent. Please click here for the full DOE document.

(Additional Edits: Judy Lin, Chief Editor, LEDinside)