Resources | White Papers | Test Equipment | Aug 30, 2017

White Paper: FluxGage - A Photometric Test System for LED Luminaires Based on Solar Panels

We present a novel photometric test system for LED luminaires. The new photometric system called „FluxGage“ uses solar panels to detect and measure light. By placing a diffuser and a black pinhole array over a solar panels we achieve a detection surface which is also an absorber. This enables the system to be the same size as the DUT (Device Under Test), as opposed to an integrating sphere which is at least 3 times larger than the DUT. Simulations and experimental results show that this system can measure total flux with an uncertainty of 4.3%. The demonstrated system is used in 2π geometry. The system measures total flux, color parameters (CCT, CRI, chromaticity, etc.) and flicker.

White Paper: INTRODUCTION (EXCERPT)

The integrating sphere is the standard instrument for measuring flux and color of light sources [1],[2]. The fundamental makings of the integrating sphere are its spherical geometry and the white diffusive coating on its interior. Integrating spheres must be at least 3 times larger than the DUT. Additionally, the effect of the DUT‘s absorption on the measurement (self-absorption) must be calibrated. With LED luminaire sizes ranging from several inches to several feet, the required integrating sphere diameter reaches 6-10 feet (2-3 meters).

The FluxGage system is based on an opposite approach a detection surface which is also an absorber, ideally absorbing every photon emitted by the DUT. With this approach, spherical geometry is not required, the measurement device can be the size of the DUT, and the measurement does not depend on the DUT.

The detection surface should have the following properties:

  •  It detects light, i.e. it transforms light into a measurable electrical signal.

  •  Light detection does not depend on angle.

  •  Very little reflection.

    The detection surface should have the following properties:

  •  A diffuser is used to reduce the angle dependence of the solar panel responsivity.

  •  A dense array of pinholes is placed over the diffuser using black matte paint, thus making most of the surface black. The light incident on the panels is therefore spatially sampled by this dense array.

 

_________________________________________________________


Download the White Paper!

 
Provided by

Efi Rotem, Raphael Cohen, Shimon Elstein, Daniel Sebbag, Ephraim Greenfield


 

_________________________________________________________

 

Supported by LED professional (c) 2017
The global information hub
for lighting technologies.

FEATURED

Lumileds RGBW Module Achieves Breakthrough Flux and Color Control

Lumileds RGBW Module Achieves Breakthrough Flux and Color Control Lumileds, a global leader in innovative lighting solutions, today introduced the Luxeon MultiColor Module 2.5 W, a compact RGBW module that produces leading flux and achieves exact color points in architectural and general outdoor lighting applications. The 4-in-1 module simplifies system design by ... Read more »

FEATURED

American Bright introduces Smart RGB Addressable Rope Light Solutions

American Bright introduces Smart RGB Addressable Rope Light Solutions American Bright brings to the market their smart RGB+IC LED flexible rope lighting solutions allowing for boundless application opportunities. The smart LED light source includes the controller and RGB chip in one package allowing for each LED to be addressable. Additional adaptability is gained ... Read more »

FEATURED

Goniometer LGS 650: Higher Accuracy and Reproducibility

Goniometer LGS 650: Higher Accuracy and Reproducibility Goniophotometry is an absolute measuring procedure that can achieve a higher level of accuracy than sphere photometry. It does not require a luminous flux standard, but in contrast is often used for calibrating standard lamps for luminous flux. In addition to the luminous flux, photometric spatial ... Read more »

FEATURED

Cree® XLamp® High Current LED

Cree® XLamp® High Current LED The XLamp High Current LED Array family is optimized for best-in-class lumen output, efficacy and reliability at high drive currents. XLamp CMA LEDs share the same package design and LES sizes as Cree's industry-leading CXA2 Standard Density LEDs, enabling lighting manufacturers to address a range ... Read more »

EDITORIAL

High Conductive Foils Enabling Large Area Lighting

High Conductive Foils Enabling Large Area Lighting Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP as one of the leading partners for research and development for surface technologies and organic electronics and Sefar AG, a leading manufacturer of precision fabrics from monofilaments, developed a roll-to-roll ... Read more »

page_peel