Agilent Cary Universal Measurement Accessory (UMA)

Significance of the topic

The Cary Universal Measurement Accessory (UMA) expands the capabilities of UV-Vis and UV-Vis-NIR spectrophotometers by enabling automated, absolute measurements of reflection, transmission and scattering over a broad angular range. This capability addresses critical needs in research, quality assurance and industrial production of thin films, coatings, optics, glass and solar components by delivering precise, unattended analysis that improves data reliability and manufacturing throughput.

Objectives and Overview of the Accessory

The UMA is designed to integrate seamlessly with Agilent Cary 4000/5000/6000i/7000 series instruments to:

• Perform absolute specular reflectance at angles from 5–85° and transmission from 0–90° in 0.02° increments.
• Measure diffuse scattering and absorptance without sample motion, using independent detector and sample rotation controls.
• Support a single baseline for all transmittance and reflectance measurements, reducing setup time.

Methodology and Instrumentation

The UMA employs high-resolution optical encoders to maintain precise angular positioning of the sample and detector. Wire-grid polarizers and adjustable apertures allow control of beam polarization and collimation. A two-color Si/InGaAs detector provides direct UV-Vis and NIR coverage without integrating spheres. The accessory supports:

• Sample diameters from 5 mm to 275 mm and thickness up to 30 mm.
• Adjustable incident cone angles (1–3°) and detector cone angles (1–6°) for fine control of beam geometry.
• Independent sample rotation (360°) and detector positioning (10–350°) for multi-modal measurements.

Main Results and Discussion

The UMA delivers:

• High accuracy and precision through stable, unattended operation and single-baseline calibration.
• Enhanced throughput by automating angle-dependent measurements without manual sample realignment.
• Reliable data quality via direct-view detection, avoiding signal attenuation from additional optics.

These features facilitate detailed optical characterization, including refractive index (n and k), film thickness, diffuse scattering profiles and absorptance, supporting both fundamental research and QA/QC workflows.

Benefits and Practical Applications

Key applications include:

• Thin film and coating uniformity control and optical constant determination in academic and industrial research.
• Quality assurance of coating performance, glass products and solar components against industry standards (e.g., EN410, ISO9050).
• Solar reflector and photovoltaic module development, optimizing material efficiency and longevity under environmental stress.

Future Trends and Potential Applications

Advances likely to enhance UMA functionality include integration with advanced data analytics and machine learning for predictive quality control, expanded wavelength detectors covering emerging materials, and automated sample handling systems to further boost throughput in high-volume manufacturing environments.

Conclusion

The Agilent Cary UMA provides a versatile, high-precision platform for comprehensive optical measurements. Its automated operation, broad angular range and high data integrity support a wide spectrum of applications from fundamental optical research to rigorous QA/QC in industrial settings, delivering time and cost savings while ensuring product quality.

Reference

Agilent Technologies Inc. Technical Overview: Cary Universal Measurement Accessory for Cary 4000/5000/6000i/7000 Spectrophotometers. Publication No. 5991-2529EN, May 2013.