HunterLab ColorFlex EZ Portable Spectrophotometer

Overview

The HunterLab ColorFlex EZ Portable Spectrophotometer is a high-precision, 45°/0° geometry instrument engineered for repeatable, human-eye-mimicking color measurement in quality control and R&D environments. Based on dual-beam spectrophotometric principles, it employs a sealed optical path with a 256-element diode array detector and a high-resolution concave holographic grating to deliver stable spectral acquisition across the visible range (400–700 nm). Its 45° circumferential illumination and 0° viewing axis replicate the angular sensitivity of human vision under standardized CIE illuminants—making it uniquely suited for evaluating surface appearance, gloss-invariant color, and metamerism-critical applications. Designed for compliance with CIE 15:2004, ISO 7724-1, ASTM E1164, DIN 5033-7, and JIS Z 8722 Condition C, the ColorFlex EZ serves as a primary or secondary transfer standard in laboratories requiring traceability to NIST-certified reference materials.

Key Features

• 45°/0° optical geometry optimized for diffuse reflectance measurement without specular component inclusion—ideal for textured, matte, or semi-gloss surfaces
• Sealed optical bench with xenon flash lamp (>1 million flashes lifetime) ensures long-term photometric stability and eliminates lamp drift-related calibration drift
• Measurement cycle completes in <1 second from trigger activation; full spectral data display within 2 seconds; minimum inter-measurement interval of 3 seconds
• 31.8 mm (1.25″) port diameter with 25.4 mm (1″) effective measurement area enables consistent sampling of solids, powders, pastes, and liquids
• Spectral resolution <3 nm (FWHM), effective bandwidth 10 nm (triangular equivalent), and 10 nm reporting interval support robust color difference calculation per CIE ΔE*_ab, ΔE*₀₀, and CMC(l:c)
• Instrument-to-instrument agreement ≤0.15 ΔE*_ab (average) and ≤0.25 ΔE*_ab (maximum) across BCRA Series II ceramic tile set—validated per ASTM E259
• Colorimetric repeatability ≤0.05 ΔE*_ab on white reference tile (20 consecutive readings), confirming suitability for tight-tolerance QC workflows

Sample Compatibility & Compliance

The ColorFlex EZ accommodates diverse sample forms—including flat solids, granular materials, opaque liquids, suspensions, and viscous pastes—via interchangeable accessories: glass sample cups (64 mm OD), port inserts for precise cup alignment, opaque lids acting as light traps, and annular/disk sample holders for particulate or powder presentation. All measurements exclude specular reflectance by default, conforming to ISO 7724-1 “specular component excluded” (SCE) mode. The system supports GLP/GMP-aligned operation through audit-trail-capable software integration and meets FDA 21 CFR Part 11 requirements when paired with compliant EasyMatch QC software. Calibration verification follows NIST-traceable protocols per CIE Publication 44 and ASTM E259, ensuring metrological integrity across global supply chains.

Software & Data Management

The instrument interfaces seamlessly with HunterLab EasyMatch QC software (Windows-based), enabling automated pass/fail tolerancing, statistical process control (SPC) charting, spectral database archiving, and customizable report generation (PDF, CSV, XML). Raw spectral data (10 nm intervals), tristimulus values (CIE XYZ, L*a*b*, L*C*h°), and full reflectance curves are exportable for third-party analysis. Software supports multi-instrument network synchronization, user-level access controls, electronic signature capture, and full audit trail logging—including operator ID, timestamp, calibration history, and parameter modifications—to satisfy ISO/IEC 17025 and pharmaceutical quality system requirements.

Applications

• Paint & coatings: Batch-to-batch color consistency validation, formulation matching, and weathering stability assessment
• Plastics & polymers: Pigment dispersion uniformity, masterbatch qualification, and extrusion line monitoring
• Food & beverages: Solid food surface color grading (e.g., cheese rinds, baked goods), liquid transparency and hue tracking (juices, sauces)
• Pharmaceuticals: Tablet coating homogeneity, capsule shell color verification, and excipient batch release testing
• Textiles & paper: Dye lot conformance, whiteness index (CIE WI), and yellowness index (ASTM E313) quantification
• Consumer electronics: Anodized aluminum, painted housings, and display bezel color matching under multiple illuminants

FAQ

What does “45°/0° geometry” mean, and why is it critical for color matching?
It refers to circumferential 45° illumination with axial 0° viewing—mimicking how the human eye perceives color under typical lighting. This geometry minimizes directional bias and suppresses specular highlights, yielding results highly correlated with visual assessment.
Can the ColorFlex EZ measure transparent or translucent liquids?
Yes—when used with the optional 64 mm glass sample cup and opaque lid, it measures transmission-mode color of clear liquids; for translucent or hazy samples, reflectance mode with diffuser-backed cup configuration is recommended.
Is NIST traceability provided with the instrument?
Each unit ships with a Certificate of Conformance referencing NIST-traceable ceramic tile standards (BCRA II set), and factory calibration is performed using instruments certified per ISO/IEC 17025.
Does the instrument support multiple color spaces and difference formulas?
Yes—it calculates CIE L*a*b*, L*C*h°, XYZ, Yxy, and Hunter L,a,b; supports ΔE*_ab, ΔE*₀₀, ΔE_CMC, ΔE₉₄, and user-defined tolerances.
How often must the instrument be recalibrated?
Daily verification with supplied white and black tiles is recommended; full recalibration is typically required every 6–12 months depending on usage frequency and environmental conditions—documented via EasyMatch’s calibration log.