The purpose of this article is to explain how the Agera L2 D65 UV400 Compare Mode helps detect optical brightening agents (OBAs) and fluorescent additives in plastics, recycled materials, and compounded resins by comparing UV-inclusive and UV-excluded measurements. This feature provides a fast, objective method for identifying UV-reactive behavior that can impact visual appearance, color consistency, and agreement between instrumental and visual evaluations
Important Notes:
- D65 UV400 Compare Mode is a fluorescence detection tool — not a pass/fail color tolerance mode
The feature is designed to identify the presence and relative impact of optical brighteners and fluorescent additives by comparing two measurements under different UV conditions. A larger ΔE between the measurements indicates stronger UV-reactive behavior. - Materials containing OBAs can appear visually different under changing lighting conditions
Optical brighteners absorb UV energy and emit visible blue light, increasing perceived whiteness and brightness. Variations in UV content between light sources can cause the same material to appear different between production sites, laboratories, or customer environments. - The new UV400 Compare workflow simplifies fluorescent material evaluation compared to previous methods
Earlier workflows relied heavily on spectral plot interpretation using a 420 nm compare approach. The D65 UV400 Compare feature provides a more intuitive and meaningful ΔE comparison, allowing operators to identify fluorescent behavior quickly without advanced spectral analysis expertise.
Modern plastic resins, recycled materials, and compounded formulations increasingly contain optical brightening agents (OBAs) and fluorescent additives designed to improve perceived whiteness and visual brightness under daylight conditions. These materials can create significant visual differences that are not always obvious in standard color measurements unless UV behavior is specifically evaluated.
The Agera L2 with Essentials L2 includes D65 UV400 Compare Mode designed specifically to identify the presence of OBAs and fluorescent behavior quickly and objectively.
How D65 UV400 Compare Works
The workflow is intentionally simple:
- The sample is placed on the measurement port
- Two consecutive measurements are automatically performed:
- First measurement: full D65 spectrum including near UV (360–700 nm)
- Second measurement: visible-only measurement with UV removed (400–700 nm)
- Essentials L2 automatically calculates and displays the ΔE difference between the two measurements
Interpretation of Results
- Minimal or no ΔE difference:
- Indicates little to no fluorescent response
- OBAs are likely not present
- Significant ΔE difference:
- Indicates UV-reactive behavior
- OBAs or fluorescent additives are present in the material
Why This Matters
Optical brighteners absorb UV energy and re-emit visible blue light, increasing perceived whiteness and brightness. As a result:
- Materials may appear different under different lighting conditions
- Visual appearance may shift between production sites
- Recycled content may introduce unexpected fluorescence variability
- Instrument agreement with visual evaluation becomes difficult without controlled UV measurement
The D65 UV400 Compare feature provides a fast and intuitive way to identify this behavior without requiring detailed spectral interpretation.
Improvement Over Previous 420 nm Compare Method
Previous workflows relied on a 420 nm compare approach. While effective for trained users reviewing spectral plots, the resulting ΔE values were often difficult to interpret directly, requiring operators to analyze spectral curves manually to determine whether fluorescent additives were present.
The D65 UV400 Compare workflow simplifies this process significantly by:
- Providing a more meaningful ΔE comparison
- Using a full UV-inclusive vs UV-excluded measurement approach
- Allowing operators to identify fluorescent behavior immediately
- Reducing dependence on spectral expertise
👉 Impact: The D65 UV400 Compare feature enables faster detection of optical brighteners, improved troubleshooting of visual mismatches, and more reliable evaluation of recycled and UV-reactive plastic materials in real-world production environments.
Download the PDF below.
To learn more about Color and Color Science in industrial QC applications, click here: Fundamentals of Color and Appearance
Do you still need more information? Submit a ticket and our support team member will reach out to you soon!