LED Light Measurement Solution-Application

LED Light Measurement Solution

author: Susan

2022-04-24

Introduction:
The measurement of LEDs (Light Emitting Diodes) presents unique application requirements and Optosky has the appropriate instrumentation and application experience to help our customers configure their systems. Optosky has many years of experience in LED applications, which has led us to develop various system configurations to meet most LED metering requirements. Light-emitting diodes can measure a variety of colors and brightness. Therefore, accurate measurement of LEDs is critical. This can be done in two ways: photometric and radiometric.
Photometry is only concerned with visible light radiation, just like how the human eye responds. Radiation measurements go beyond these limits. In both photometric and radiometric measurements, LEDs can be characterized in terms of emitted power or intensity. The transmitted power is all the power (magnetic flux) emitted by an LED, measured in Lumens or watts, collected and measured regardless of the direction of the magnetic flux. Intensity is the ratio of fluxes that leave the source and propagate in solid angle elements containing a given direction, and are expressed in Candelas.
LED Measurement System:

For basic measurements of photopic parameters and irradiance (excluding flux), a system is typically configured with the ATP2000P spectrometers, a 25 µm slit and 500 line/mm grating covering the range from 200-1000 nm and provides 1 -1.8 nm full width half maximum (FWHM) resolution. A 2-metre fibre-optic cable (UV-VIS-1-200) is mated to the instrument and terminated in a cosine function diffuser (Cosine Correctors) which has 3.9 mm diameter surface area. The entire system is irradiance calibrated with an NIST source over the specified wavelength range for spectral irradiance (µW/cm2/nm).
This calibration system can be operated using Optoksy's proprietary LED measurement software, which provides the following parameters: X, Y, Z, x, y, z, u, v, CRI, color temperature, dominant wavelength, complementary dominant wavelength, FWHM, Centroid, peak wavelength and purity. In addition, raw data in scope mode is displayed, along with an X-Y chromaticity plot. Alternatively, the system can be configured with longer fiber lengths and a tripod to hold the diffuser in place during measurements.
The system can be controlled via LabView, C#, C++ and many other programming environments via the Optosky Dynamic Link Library (DLL) interface.
For flux measurements, the entire LED must be plugged into the port on the integrating sphere. Optoksy offers a complete range of Integrating spheres ATST150 ranging from 30-200 mm (inside diameter). For system calibration, Optosky offers the ATG100 calibration source in a configuration compatible with cosine diffusers and small integrating spheres (30, 50, 80 mm).

LED Light Measurement Solution

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