What does a good photometric report cost?

[Jeff Engel]

We are seeing so many new LED downlight fixtures from big and small
manufacturers. The specs are pretty hard to compare, if there are any
photometric specs at all. What is missing? Do we all agree that there
is a single standard test with a report tabulation that would be
sufficient for informed comparisons of LED downlights? We're seeing
full page ads for fixtures that cost 10's of thousands of dollars, but
we're not getting certified photometric tests that cost relatively
little. I guess it'll never be as simple as the EPA city/highway MPG
ratings, but can't we get something vaguely reliable for comparison?
Isn't there a test that could become the sine qua non for specifiers? Is
CaLIPRE working well enough to become this standard?

 

[boxman]

We are seeing so many new LED downlight fixtures from big and small
manufacturers. The specs are pretty hard to compare, if there are any
photometric specs at all. What is missing? Do we all agree that there
is a single standard test with a report tabulation that would be
sufficient for informed comparisons of LED downlights? We're seeing
full page ads for fixtures that cost 10's of thousands of dollars, but
we're not getting certified photometric tests that cost relatively
little. I guess it'll never be as simple as the EPA city/highway MPG
ratings, but can't we get something vaguely reliable for comparison?
Isn't there a test that could become the sine qua non for specifiers? Is
CaLIPRE working well enough to become this standard?

I believe that's the purpose of LM-79-08 from the IES. DOE lists it on
their website as the test procedures to be used for photometrics on
Solid State Lighting

http://www1.eere.energy.gov/buildings/ssl/newtest.html

Any legitimate manufacturer of LED lighting assemblies will have this
test data available. If they don't have it, don't use them.

 

[TKM]

Yes, the Caliper data is quote good and can generally be
trusted. However, Caliper tests only a small fraction of
the products on the market.

As Boxman said, their is now a standard test protocol for
luminaire efficacy, the same one used for the Caliper data,
and you should demand that any vendor provide results per
that standard.

Photometry involving LEDs is more complex and expensive because the
photometer has to be calibrated to measure actual lumens (absolute
photometry) rather than the traditional relative photometry which does not
depend upon calibrated lamp standards.

There's a certification program called NVLAP that the DOE also requires for
LED photometric tests. See:
http://ts.nist.gov/standards/accreditation/summary.cfm and the relatively
small number of laboratories that can do the work:
http://ts.nist.gov/standards/scopes/eelit.htm

Costs for photometric tests vary widely and depend to a great extent upon
the size and type of luminaire. If a photometric test for a particular
luminaire is not available, the traditional reason is because the luminaire
is designed for the residential market and it's low price points. That is
changing, however, and photometry is the norm for LED luminaires. The lack
of a photometric report for an LED luminaire such as a downlight certainly
raises questions about the performance of the product.

Terry McGowan