Labsphere PERMAFLECT® Diffuse Reflectance Coating

Overview

PERMAFLECT® is a high-performance, engineered diffuse reflectance coating developed by Labsphere — a globally recognized leader in optical calibration standards and integrating sphere technology. Designed for precision photometric, radiometric, and spectroscopic applications, PERMAFLECT® operates on the principle of near-ideal Lambertian scattering across an exceptionally broad spectral range (250–2500 nm). Its formulation delivers stable, isotropic bidirectional reflectance distribution function (BRDF) characteristics essential for traceable optical calibration. Unlike conventional barium sulfate or PTFE-based coatings, PERMAFLECT® is chemically bonded to substrates via proprietary surface preparation and thermal curing, resulting in superior mechanical durability, environmental resistance, and long-term spectral stability — critical for integration into industrial-grade optical systems operating under thermal cycling, vibration, or abrasive conditions.

Key Features

• Ultra-broadband spectral performance: 250–2500 nm coverage, with optimal Lambertian behavior in the visible–NIR region (350–1200 nm)
• Multiple calibrated reflectance grades: Available in nominal diffuse reflectance values of 18%, 50%, 80%, and 94% (measured per ASTM E1331 and ISO 2813 at 5° geometry)
• Enhanced environmental resilience: Resistant to weathering, abrasion, and moderate humidity; rated for continuous operation up to +80 °C
• Substrate versatility: Optimized for metal (aluminum, stainless steel) and glass substrates; compatible with select thermoset plastics following pre-adhesion validation
• Controlled outgassing profile: Meets NASA low-outgassing specifications (ECSS-Q-ST-70-02C) for vacuum-compatible applications; exhibits minimal volatile condensable material (VCM) release below 1×10⁻⁶ g/cm² in <10⁻⁵ Torr environments
• Factory-applied or field-deployable: Applied in Labsphere’s ISO 9001-certified coating facility; on-site application support available for large-scale or geometrically complex integrations

Sample Compatibility & Compliance

PERMAFLECT® requires rigorous substrate preparation — including solvent degreasing, grit blasting (Al₂O₃, 60–120 mesh), and thermal stabilization — to ensure adhesion integrity and BRDF uniformity. It complies with industry-standard optical calibration protocols referenced in NIST SP 250-88, ISO/IEC 17025:2017 (for accredited calibration labs), and USP for photometric system qualification. While not intended for UV-dominant applications (<350 nm), its 250–350 nm performance is validated for specific aerospace sensor characterization workflows under MIL-STD-810H Section 505.5. The coating is non-hazardous per GHS classification and RoHS-compliant (Directive 2011/65/EU).

Software & Data Management

Labsphere provides certified BRDF datasets (in ASCII and HDF5 formats) for each reflectance grade, traceable to NIST SRM 2032 and 2035. These files are fully compatible with common optical simulation platforms including LightTools®, FRED®, Zemax OpticStudio®, and TracePro®. All datasets include full uncertainty budgets (k=2), angular sampling resolution ≤0.5°, and wavelength step intervals of 1 nm. For GLP/GMP-regulated environments, Labsphere supplies audit-ready documentation packages including lot-specific coating certificates, application process logs, and post-cure spectral verification reports — compliant with FDA 21 CFR Part 11 electronic record requirements.

Applications

• Integrating sphere inner surface coating for photometric and radiometric calibration sources
• Reference standards for spectrophotometer linearity verification (per ISO 13406-2 Annex B)
• Stray light suppression surfaces in spaceborne optical payloads and terrestrial lidar receivers
• Uniform illumination targets for machine vision system validation (ISO 16067-1)
• Calibration reference for NIR spectroscopy sensors in pharmaceutical QC and agricultural analysis
• Diffuse reflectance standards in medical imaging device testing (IEC 62220-1-2 for flat-panel detectors)

FAQ

Is PERMAFLECT® suitable for vacuum ultraviolet (VUV) applications below 200 nm?
No. PERMAFLECT® is not formulated for VUV stability; degradation and carbonization occur below 250 nm. For VUV use, Labsphere recommends Spectralon® VUV or custom cerium-doped quartz coatings.
Can PERMAFLECT® be reapplied over an existing coated surface?
Not without complete mechanical removal and re-preparation. Re-coating over degraded or contaminated layers compromises adhesion and BRDF fidelity.
What is the shelf life of unapplied PERMAFLECT® coating material?
When stored sealed under inert gas at 15–25 °C, the uncured formulation maintains specification compliance for 12 months from date of manufacture.
Does Labsphere provide reflectance certification for customer-applied coatings?
Yes — upon request, Labsphere offers third-party spectral validation services using NIST-traceable double-monochromator spectrophotometers (PerkinElmer Lambda 1050+ with 150 mm integrating sphere), with full ISO/IEC 17025 test reports.