Labsphere RSA-FO-150 Fiber-Optic Single-Beam Reflectance Integrating Sphere

Overview

The Labsphere RSA-FO-150 is a compact, fiber-optic–coupled integrating sphere designed for accurate and repeatable measurement of hemispherical reflectance across an ultra-broad spectral range—from deep ultraviolet (250 nm) through visible and near-infrared up to short-wave infrared (2500 nm). Engineered for compatibility with commercially available spectrometers and broadband light sources, the RSA-FO-150 implements an 8°/hemisphere optical geometry per ASTM E1331 and ISO 2813 standards. It operates on the principle of diffuse light collection: incident radiation strikes the sample at 8° from normal incidence, and total reflected flux—both specular and diffuse components—is captured by the sphere’s highly Lambertian inner surface and delivered via SMA 905 fiber to the detector. The sphere’s core function is to enable quantitative reflectance characterization of both specular and diffuse materials under standardized illumination and collection conditions, supporting traceable calibration workflows in R&D, quality control, and regulatory-compliant material testing labs.

Key Features

• Spectralon®-coated interior (≥99% diffuse reflectance from 250–2500 nm), ensuring high signal-to-noise ratio and long-term photometric stability
• 8°/hemisphere measurement geometry compliant with ASTM E1331, ISO 2813, and CIE 15:2018 for total reflectance quantification
• Dual SMA 905 fiber ports: top-angled input port (8° incidence) and side-mounted output port (90° relative to sample plane) for optimal spectral coupling
• Integrated specular reflectance trap: manually actuated via thumbscrew to expose or occlude a calibrated light-absorbing cavity—enabling switchable measurement modes (total vs. diffuse-only reflectance)
• Knife-edge sample port design minimizes edge diffraction and maximizes collection efficiency for wide-angle scattered light
• Robust aluminum housing with black-anodized exterior and internal thermal stabilization—suitable for benchtop, portable, and field-deployable use

Sample Compatibility & Compliance

The RSA-FO-150 accommodates flat, rigid samples up to 38 mm in diameter (standard port size), including coated optics, paints, pigments, thin films, solar absorbers, and biological tissue phantoms. Its geometry supports both opaque and semi-transparent substrates when used with appropriate backing (e.g., Spectralon® reference tile or black trap). All measurements are traceable to NIST-traceable reflectance standards, and the system is routinely validated using Labsphere’s certified reflectance reference tiles (e.g., STS-1000 series). The device meets mechanical and optical requirements for GLP and GMP environments, and its modular interface enables integration into automated test benches compliant with FDA 21 CFR Part 11–enabled software platforms when paired with validated spectrometer controllers.

Software & Data Management

The RSA-FO-150 requires no proprietary firmware or embedded electronics—it functions as a passive optical interface. Reflectance data acquisition is fully managed through the host spectrometer’s OEM software (e.g., OceanInsight OceanView, Avantes ASE, or StellarNet Black-Comet Suite). Users perform two sequential acquisitions: one with the sample in place and one with a calibrated reference standard (e.g., >99% Spectralon®). Reflectance (%) is computed as R(λ) = [I_sample(λ)/I_ref(λ)] × R_ref(λ), where R_ref(λ) is the certified spectral reflectance curve of the standard. Raw spectral files (CSV, TXT, or vendor-specific binary formats) retain full wavelength and intensity metadata, supporting post-processing in MATLAB, Python (NumPy/SciPy), or commercial analysis tools such as OriginLab or JMP. Audit trails, user authentication, and electronic signatures can be implemented at the spectrometer software layer for regulated applications.

Applications

• Development and validation of anti-reflective, high-reflectance, and selective-spectrum coatings for aerospace optics and laser systems
• Colorimetric and spectral reflectance analysis of architectural paints, automotive finishes, and printed packaging per ISO 12647 and ASTM D2244
• Photovoltaic material characterization—including spectral absorptance of solar cell absorbers and reflectance of backsheet films
• Biomedical optics: quantification of tissue-mimicking phantom reflectance for optical coherence tomography (OCT) and diffuse reflectance spectroscopy (DRS) calibration
• Quality assurance of ceramic glazes, polymers, and powder-based pigments in manufacturing environments requiring ISO/IEC 17025–accredited testing
• Environmental monitoring: albedo measurement of snow, soil, and vegetation surfaces in field-deployable UV–NIR reflectance setups

FAQ

What spectrometers are compatible with the RSA-FO-150?
The RSA-FO-150 interfaces with any spectrometer equipped with SMA 905 fiber input and spectral coverage spanning 250–2500 nm—including CCD, CMOS, and InGaAs-based detectors.
Can I measure bidirectional reflectance distribution function (BRDF) with this sphere?
No—the RSA-FO-150 is optimized for hemispherical total reflectance only; BRDF requires goniometric scanning systems with motorized angular positioning.
Is calibration service available for the RSA-FO-150 itself?
The sphere does not require factory calibration; however, Labsphere provides NIST-traceable reflectance standards and application support for user-performed system-level validation.
How is stray light minimized in the 8° input configuration?
The 8° angled port prevents direct illumination of the output fiber port and suppresses first-order specular reflections from reaching the detector without passing through the integrating sphere wall.
What is the maximum sample thickness supported?
Samples must be planar and ≤3 mm thick to ensure full seating within the knife-edge port; thicker specimens require custom port adapters (available upon request).