VARIABLE ATTENUATORS

For Precise Control of Light Entering an Integrating Sphere

FEATURES:

• Test Detector/Sensor Linearity over Large Dynamic Range
• Achieve Spectral Neutral Light Intensity Control
• Precisely Vary the Amount of Light Entering an Integrating Sphere
• For use with Labsphere Luminance/Radiance and XTH - Xenon Source Systems

Variable Attenuator Assemblies (VA) are mechanical, spectrally neutral "irises" that allow precision control of light entering into a sphere. In turn, the precise input control gives corresponding control of the light level emitted from the sphere port while minimizing color shifts in the output spectrum. Our VA Series Variable Attenuators include both manual and automated models. The VA-MM Manual Variable Attenuator is a standard component of our LR Luminance Radiance Spheres and Systems. The VA-HR models are offered as optional upgrades when higher resolution, and automation are required for an application. Each VA is designed with a novel asymmetrical aperture that allows for higher resolution adjustment at lower light levels.

VARIABLE ATTENUATOR MODELS AVAILABLE

VA-MM – Manual Micrometer Control
Incorporates a non-rotating micrometer-driven shaft to move the attenuator blade across a fixed aperture. Provides >20,000 steps, with ~5 decades of dynamic range, for precise control of light levels.

VA-HR – Precision, Dynamic Range and Flexibility
Our highest performance attenuator - the VA-HR offers the most resolution, dynamic range and repeatability of any variable attenuator on the market today. The VA-HR is a computer controlled unit that utilizes a linear drive motor and optical encoder for movement and positioning. The VA-HR is supplied with a controller unit for communication with a computer. The methods of communication with this device are using our Luminance/Radiance System Software, L/R system Dll, a Copley Controls Corp CME2® or a terminal emulator. The ASCII command set allows the user to communicate with the controller without having to develop any additional software. The high resolution mode provides up to 2.1 million steps, while the other provides up to 9000 steps; both operating modes provide ~8 decades of dynamic range.

SPECIFICATIONS AND ORDERING INFORMATION