Product Selection Guide Page 1107 Product Selection Guide-11th Edition

1107 PRODUCT INFORMATION Binning LED TECHNICAL INFORMATION PSG11 TECHNICAL INFORMATION The coating processes (epitaxial growth and phosphors) create significant inherent variations that impact the lumens, color temperature and voltage of the LEDs. In an effort to maximize yields (and with a knowledge that the lighting industry has a wide range of needs), LED manufacturers sort their production into lumen, color and sometimes voltage bins. This allows luminaire manufacturers to select only those LEDs that meet their acceptable performance ranges while maximizing the overall utilization of the very expensive LED production equipment. It is worth noting that with the heavy investment in R&D, LED manufacturing has become significantly more controlled. Bin ranges today are significantly tighter than they were a few short years ago. If a luminaire manufacturer accepts a very wide range of LEDs (in any of the binned criteria), price and lead time are substantially improved. On the downside, the variability of luminaire performance is substantially increased, creating high probability for negative impact to end-use customers. This point becomes extremely important as we discuss key elements of fixture performance (photometry, energy use, color, etc). As stated previously, there are several ways LEDs are binned. The most critical bin criteria that impact product performance are light output and color temperature. Binning for light output is a very straightforward linear function. LEDs are individually measured and sorted by lumen output into prescribed ranges. LED suppliers create their own standard set of lumen bins and provide clear information on the expected lumen performance of each of their bin ranges. So, luminaire manufacturers can easily select the bin (or set of bins) that best meets the lumen performance requirements of the fixture. Binning for color temperature is a more complex process. Color temperature bins (shown on page 1108) are defined by (x,y) coordinates on the CIE 1931 Chromaticity Diagram (shown at right).

Previous Page
Next Page