The VW SRA is designed to measure the direct (specular)

refl ectance of light from smooth solid materials at near normal

incidence. The term “VW” describes the light path through the

accessory in the reference and measurement positions. The VW

design features a kinematically mounted spherical mirror, which

is used for both calibration and sample measurement. With the

exception of the sample, the same optical elements are always in

the light path, providing a truly absolute refl ectance measurement.

Absolute measurements remove any need to correct results against

standard reference materials.

The VW optical design also provides the functionality necessary for:

• Real time comparison of coated and uncoated substrates• Refl ectance, transmittance and absorptance measurements without

touching the sample• Transmittance determination on highly transparent fi lms using a double

pass through the sample when in the “V” measurement position• Single bounce refl ectance measurement confi guration for extreme AR

coatings (< 0.1 %R)

AGILENT VW ABSOLUTE SPECULAR REFLECTANCE ACCESSORYFOR THE CARY 100/300/4000/5000/6000i UV-VIS-NIR SPECTROPHOTOMETERS

Obtain high precision absolute specular refl ectance measurements

Optical diagram of the dual view Cary VW SRA accessory for the Cary 4000/5000/6000i

1. Incident light

2. Movable spherical mirror

3. Sample

For more information:www.agilent.com/chem/uv

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CUUUULAR

0/55000/600METERS

ar refl ectance measurements

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Agilent Products are for Research Use Only.Not for use in diagnostic procedures.

Information, descriptions and specifi cations in thispublication are subject to change without notice.

© Agilent Technologies, Inc. 2013Published in USA, April 1, 2013

5991-1726EN

Specifi cations

Instrument Cary 100/300/4000/5000/6000iWavelength range Equal to host instrumentSample sizes Minimum diameter 12 mm,

Maximum diameter 100 mmAccuracy Better than 1% refl ectanceAngle of incidence 7 degrees

Additional Accessories

Required Extended sample compartmentOptional Automated rear beam attenuator

ApplicationsThe VW SRA is ideal for the analysis of high or low refl ectance materials, and is also suitable for transmittance and absorptance measurements. It can be used for the characterization of laser mirrors, refractive index determinations, fi lm/coating thickness measurement and calculation of optical constants.

The accessory features a ‘VW’ confi guration, with one spherical mirror, and two toroidal mirrors. The movable mounting of the spherical mirror allows it to be used for both calibration and sample measurement ensuring the same optical components are in the light path during both calibration and measurement. When a sample is mounted, the only change in the system is due to the refl ectivity of the sample. An absolute value of the refl ectance is easily obtained.

Sample Example measurementThin fi lms Transmittance, refl ectance,

absorptanceAnti-refl ection coatings

Measuring coating effi ciency

Metals/alloys Thickness, optical constantsLaser mirrors Refl ectance effi ciencyArchitectural glass Modeling thermal properties

For more information:

www.agilent.com/chem/uv

Schematic of accessory showing incident light (black) at 7 degrees to sample

surface and refl ected light (blue)