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Cree Reports 131 lm/W White LED

V

Victor Roberts

Jan 1, 1970
0
Those of you who have read my posts in this group know that
I am skeptical of many LED performance reports, and also
don't like "science via press release" since too many
important details can be left out. However this one is hard
to ignore.

http://www.cree.com/press/press_detail.asp?i=1150834953712

Cree has a reputation for honest data and I doubt they would
say their data had been confirmed by NIST of it had not
been. Note that this is a 20 ma LED. I would like to see
the actual power in and light output data, but this is all I
have right now. They don't say if this is a blue (or UV) +
phosphor LED or uses three or more monochrome chips. (Though
reading between the lines suggests a multi-chip system.)
They also don't give the CRI, but 131 lm/W is still quite
impressive.

--
Vic Roberts
http://www.RobertsResearchInc.com
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V

Victor Roberts

Jan 1, 1970
0
Those of you who have read my posts in this group know that
I am skeptical of many LED performance reports, and also
don't like "science via press release" since too many
important details can be left out. However this one is hard
to ignore.

http://www.cree.com/press/press_detail.asp?i=1150834953712

Cree has a reputation for honest data and I doubt they would
say their data had been confirmed by NIST of it had not
been. Note that this is a 20 ma LED. I would like to see
the actual power in and light output data, but this is all I
have right now. They don't say if this is a blue (or UV) +
phosphor LED or uses three or more monochrome chips. (Though
reading between the lines suggests a multi-chip system.)
They also don't give the CRI, but 131 lm/W is still quite
impressive.

I contacted a member of the photometry group at NIST to see
if they could tell me any more about the Cree LED
measurements. This individual could not provide any more
data since NIST provides "calibration" services for
industrial customers on a fee-for-services basis that is
outside their normal public funds-supported role. Data
generated in this manner is proprietary to the customer.

However, I was reading a bit about the calibration services
at www.nist.gov and Cree may have violated NIST policy
regarding use of the results of their measurement services
by quoting them in a press release. See
http://ts.nist.gov/ts/htdocs/230/233/calibrations/Policies/policy.htm
and scroll down to the paragraph titled: "References to
NIST in Advertisements." I would certainly consider the
Cree press release to be an "advertisement" but it is not
clear if stating that the data has been "validated by NIST"
constitutes an implied approval or recommendation. I think
it does, or at least comes very close, but others may
disagree.

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.
 
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