Testing LEDs for Automotive Use
 First in Full Range PDA Spectrometer, Spectroradiometer and Spectrophotometer Systems
1 Canal Street  ◊  Unit B1
Lawrence, MA 01840  USA
Tel: 978 687-1833  ◊  Fax: 978 945-0372
Email:
info@spectralevolution.com


Copyright © 2012 Spectral Evolution, Inc
The SR-3501, SR-1901, and SR-1901PT are field portable spectroradiometers that can be used to
measure and compare the spectral radiance of an LED (red) versus a halogen(blue) light source. This
capability becomes especially important in those applications where a design engineer is considering
replacing a traditional light source with an LED and needs to verify that the LED luminaire will meet or beat
the critical characteristics of the conventional lamp.
According to industry reports, the use of LEDs in headlamps and
running lights will increase from 5% in 2015 to 70% by 2019.
What's driving this trend? LEDs offer superior design flexibility,
better power efficiency and longer life, and better dimming and
traditional lighting alternatives, these are expected to reach
parity with traditional lights by 2019.

One of the trade-offs with LEDs is the inconsistency of lumens,
color temperature and voltage in the finished product. Output
even within a single batch can vary. LED manufacturers handle
the inconsistencies by testing and binning LEDs according to
lumens, color and voltage. Testing is therefore a criticalpart of
the manufacturing process and the combination of LEDs into
packages and luminaires.

A SPECTRAL EVOLUTION spectroradiometer  measures the
wavelengths of individual colors of light. In LED metrology it can
measure output in lumens, watts, moles per second, footcandles,
and more. A portable UV/VIS/NIR spectroradiometer  provides a
useful tool for quickly testing and characterizing LEDs and LED
luminaires. It can test an LED for optical output in watts as a
function of varying LED current, temperature, and other optical
characteristics to completely characterize the LED or LED system.

All SPECTRAL EVOLUTION systems have the following colorimetry
capabilities built-in:
  • CIE 1931 chromaticity diagram with RGB gamut
  • Scan results displayed graphically with a cross hair overlay
  • Text display of X, Y, XYZ, and RGB coordinates and
    correlated color temperature

The ability to quickly test for brightness and chromaticity in the
lab or in the field allows for rapid screening of LEDs before use
and offers a method for gauging color shift over projected
lifecycle, where color and hues are critical. Since LEDs tend to
shift color over time, measuring color stability can be a key in
many applications. It is also useful to compare the brightness
and color of LEDs versus incandescent, fluorescent or halogen
lamps early in the design process, before the LEDs are used as
substitutes for these conventional lighting technologies.
DARWin SP Data Acquisition software provides a built-in colorimetry capability. It can be used
to calculate chromaticity coordinates and correlated color temperature of a spectral dataset.
The following colorimetry capabilities are built-in:
  • Scan results displayed graphically with a cross hair overlay
  • Text display of x, y, XYZ, and RGB coordinates and correlated color temperature
SPECTRAL EVOLUTION CORPORATE LOGO - FIRST IN UV-VIS-NIR SPECTROMETER, SPECTRORADIOMETER AND SPECTROPHOTOMETER PRODUCTS
 First in Full Range PDA Spectrometer, Spectroradiometer and Spectrophotometer Systems