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Introduction
This tool will check whether the SSL (solid state lighting) product meets the Energy Star color uniformity and chromaticity specification.
This tool uses the method of calculation, angle and weighted average definitions as per IESNA LM-79-08, section 12.
Input data
Input data must have theta angles EQUALLY divided from 0deg to 180deg with 90deg being the top of the light source.
The first column must be intensity (cd) or illuminance data (lm/m2)
The second column must be the chromaticity x
The third column must be the chromaticity y
A sample data is shown below:
2.516 0.4235 0.3915 <-- first row of data at theta equals to 0deg
2.905 0.4238 0.3913 <-- second row of data at theta angle equals to 180/n,
where n is the number of equal steps.
. . .
. . .
. . .
1.846 0.4198 0.3875 <-- last row of data at theta equals to 180deg.
In some cases where a limited theta range is available, you need to patch (0, 0, 0) data to your input data for the tool to process the data correctly. The patch data must be in equal theta step sizes to fill a 0 and 180deg range. For example, a user has limited data taken at 5deg intervals from 50deg to 130deg.
The input data should look like this:
0 0 0 } patch 0, 0, 0 data at 0deg
0 0 0
. . .
. . .
0 0 0 } patch 0, 0 ,0 data at 45deg
2.516 0.4235 0.3915 <- theta = 50deg
2.905 0.4238 0.3913 <- theta = 55deg
. . .
. . .
. . .
1.846 0.4198 0.3875 <- theta = 130deg
0 0 0 } patch 0, 0, 0 data at 135 deg
. . .
. . .
0 0 0 } patch 0, 0, 0 data at 180 deg
Once the data is correctly formatted, copy and paste the data into the data input box of the tool's main page. Click the "Start Processing" button to generate the report.
Output data
The output of the result is summarized in a pdf file. Only data points that meet the minimum 10% peak intensity are shown and will be considered when determining ENERGY STAR compliance (reference: LM-79-08).
Limitations
This tool will only calculate one phi angle at a time. If there are multiple phi angles, there are two options:
1) check every phi angle to see if there is a condition that is not compliant with the ENERGY STAR specification or
2) take an average of all phi angles for each theta angle.
As a minimum, per LM-79-08, it is recommended to have at least two phi angles taken (0 and 90deg) and at least a 10 deg minimum interval for the theta angle.