LED TEST & MEASUREMENT APPLICATIONS
The optical test and measurement of LEDs involves the measurement of the light output, color or spectral characteristics of the device under test as a function of drive current, viewing angle, or other conditions. Simple tests yield a single data point; more complex tests yield a function relating an optical value to another parameter: For example, optical power as a function of drive current, or color as a function of angle.
Simple Photometric Measurements may be performed with a photometer or a spectroradiometer. Tests in this category include:
- Luminous Flux (lumens)
- Luminous Intensity (candela)
Simple Radiometric Measurements may be performed with a radiometer or a spectroradiometer. Tests in this category include:
- Radiant Flux (Watts)
- Radiant Intensity (W/sr)
Simple Color Measurements for LEDs require the use of a spectroradiometer. Tests in this category include:
- Chromaticity
- CCT (Correlated Color Temperature)
- CRI (Color Rendering Index)
- Dominant Wavelength & Purity
Simple Spectral Measurements require the use of a spectroradiometer. Results include:
- Spectral Power Distribution (SPD)
- Spectral Intensity Distribution
- Peak Wavelength
- Spectral Bandwidth (FWHM)
More Complex Tests: Sensors can be integrated with positioning systems, variable power supplies, temperature sensors, and other components to support more complex device characterization, including:
- LIV (Light Output vs. Current (I) and Voltage)
- Angular Distribution
- Thermal Coefficients
- Lifetime
Binning: The results of such testing can be used to sort devices into bins (aka groups or ranks) according to specifications including:
- Light Output (Luminous Flux or Luminous Intensity)
- Chromaticity
- Dominant or Peak Wavelength
UDT Instruments offers a range of complete, pre-configured solutions to meet the most common LED test and measurement requirements. Specialized configurations, and custom designs are also available.
