Luminance / Radiance Uniform Light Sources

Multiple Output Levels and Modular Design Features

APPLICATIONS:

• Calibration of Photometers and Radiometers
• Calibration for Spectral Radiance and Irradiance
• Calibration and Testing of Electronic Imaging Devices
• Flat Field Testing
• Detector Linearity Testing
• Solar Simulation

Labsphere Luminance/Radiance Uniform Light Source Systems are integrating sphere uniform light sources designed to accommodate a wide range of applications from night vision to remote sensing. Integrating spheres provide a near perfectly uniform source of radiance or irradiance for testing and calibrating telescopes, imaging detectors, photometers, radiometers and many electronic imaging devices.

Luminance/Radiance Systems are available in sphere sizes ranging from 4 inches (10 cm) to 76 inches (2 m), each optimally designed with an output port diameter to provide luminance uniformity of ±1%. All systems are equipped with a light source assembly, variable attenuator, power supplies, detectors and operating software. The standard variable attenuator provided with all systems is a manually driven micrometer unit that allows for control of input light levels while keeping the spectral shape fixed. An automated variable attenuator and controller unit is available when more precise control of the light output level is required.

System Calibration

Luminance/Radiance Systems are calibrated for luminance and correlated color temperature. Calibrations are traceable to national laboratory standards. Custom calibrations are available.

Download Datasheet

L/R-USS Software

Monitor and Control System Performance to Best Achieve Your Application

SOFTWARE FEATURES:

• Achieve variable output levels while maintaining consistent color temperature
• Self monitoring of luminance in fL and cd/m2 and color temperature
• Monitor spectral radiance at specified wavelength with systems calibrated for spectral radiance
• Powerful menu driven software

Application software provided with the systems operates in a convenient Windows^® environment and is used to control and monitor light output. The software allows users to turn lamps on and off individually and monitor the voltage and current of the light source. The detector current calculated luminance and correlated color temperature are monitored in real time so that output can be precisely adjusted. Systems with the automated variable attenuator control option allow users to select and drive luminance values via a software feedback control that is linked to a luminance monitor.

Optional Accessories

Filter/Target Holders for Exit Port
Filter/Target Holders are used to mount a filter in front of a detector or sphere port. Filter holders accommodate different filter thicknesses, or a stack of filters up to 0.375 inches. The filter holders mount easily to the mounting ring designed into all integrating sphere ports.

6 and 12 Position Filter Wheels and Controllers
Filter Wheels and Controllers can be mounted in front of a detector or sphere port. They are used to either manually or automatically switch between up to 6 or 12 different filters or aperture sizes. Filter wheels accommodate different filter thicknesses, or a stack of filters up to 0.375 inches. The filter apertures are sized for either 1" or 2" diameter ports.

Automated Variable Attenuator
Variable attenuators are used to vary the intensity of an external light source entering the sphere, while minimizing color shifts in the output spectrum. The automated variable attenuator is a motorized attenuator that includes an aperture controller module, and is operated through the system software. A dual channel attenuator is also available for applications requiring more than one type of lamp, such as our Tungsten-Halogen Xenon Systems.

SMS-LR-USS Spectral Measurement System
The SMS-LR-USS option for the LR-USS series allows the user to monitor the spectral output of the sphere in real time. The SMS-LR-USS spectral monitor will track changes in the output due to age of the lamp or changes induced by the variable attenuator. Furthermore, if the LR-USS system contains a xenon source, spectral monitoring is needed to track the luminance of the output. When using the automated variable attenuator option, the SMS-LR-USS has the ability to "Hunt and Seek" the desired luminance output, while still spectrally monitoring the source.

Custom Capabilities

Labsphere engineers have years of experience designing and manufacturing high value standard and customized luminance and radiance uniform light source systems. Our optical, electrical, mechanical and software engineers will work with you to design and build a customized system that meets your requirements.

Vacuum Compatible Radiance Sources

For characterization of sensors under vacuum environment

Ambient optical testing using spheres is a well established technique in many programs, but recent testing shows optical tests in a vacuum environment gives lower uncertainty and better correlation between calibration and execution of space flight systems. Labsphere has designed and built Vacuum Compatible Radiance Sources for use in a vacuum chamber to carry out radiometric characterization and calibration of electro-optical sensors under controlled temperature and vacuum environment. We have the capabilities to meet your needs with customized vacuum compatible systems in sphere sizes up to 2 meters. Labsphere is the only manufacturer who can deliver Vacuum Compatible Radiance Calibration Sources. This is a highly sought after capability for testing and calibration of sensors and cameras that are placed on satellites for natural resource monitoring and weather forecasting because it allows for radiometric calibration under the atmospheric conditions under which they operate.

Ask one of our technical sales engineers for information on design and development of a Vacuum Compatible Radiance Source for your application.

Ordering Information and Specifications

SPECIFICATIONS FOR HIGH RADIANCE MODELS – for Remote Sensing Applications

SPECIFICATIONS FOR MEDIUM RADIANCE MODELS - for Machine Vision and Inspection Applications

SPECIFICATIONS FOR LOW RADIANCE MODELS – for Night Vision Applications

OPTIONAL SYSTEM CALIBRATIONS

Download a copy of our Guide to Uniform Light Source Applications

Click here to download a reprint of our 2008 SPIE Optics and Photonics presentation: Vacuum Compatible large uniform-radiance source for ground calibration of satellite cameras inside thermal vacuum environment for information on one such system our engineers designed.