ATAGO RX-007α Low-Concentration Liquid Refractometer

Overview

The ATAGO RX-007α Low-Concentration Liquid Refractometer is a precision optical instrument engineered for high-accuracy refractive index and Brix measurements in dilute aqueous solutions—particularly those with total soluble solids (TSS) below 5.000%. It operates on the principle of critical angle refraction, where incident light passes through a sample placed on a sapphire prism and undergoes total internal reflection at the prism–sample interface. The resulting shadow line position is optically detected and converted into a digital RI or Brix value via calibrated algorithms. Designed specifically for low-concentration applications—including tea infusions, herbal extracts, functional beverages, and process streams in bioprocessing—the RX-007α delivers trace-level resolution without requiring sample dilution or complex calibration routines. Its integrated Peltier-based temperature control ensures measurement stability across ambient fluctuations, while automatic temperature compensation (ATC) adheres to ISO 2173 and AOAC 932.12 standards for refractometric analysis.

Key Features

• Precision optical system with sapphire measuring prism for exceptional scratch resistance and long-term calibration stability
• Dual-mode digital display: simultaneous readout of refractive index (RI) and Brix (%) with 0.00001 RI / 0.001% Brix resolution
• Integrated Peltier temperature control (range: 10–40 °C) with ±0.1 °C regulation accuracy, enabling reproducible measurements independent of lab ambient conditions
• Automatic temperature compensation (ATC) compliant with ISO 2173:2003 and ASTM D1218–16 for aqueous sucrose solutions
• Minimal sample requirement: only 2–3 drops (≈0.05 mL) per measurement, reducing waste and enabling rapid sequential analysis
• Robust benchtop architecture with IP54-rated enclosure for use in QC laboratories, pilot plants, and regulated production environments

Sample Compatibility & Compliance

The RX-007α is optimized for transparent, low-viscosity liquids with refractive indices between 1.330150 and 1.341500—corresponding to Brix concentrations from 0.000% to 5.000%. It is routinely deployed for quality assurance of tea extracts, green juice concentrates, probiotic broths, electrolyte solutions, and low-sugar beverage formulations. The instrument supports GLP-compliant workflows through user-accessible calibration logs, date/time-stamped measurement records, and password-protected method settings. While not FDA 21 CFR Part 11–certified out-of-the-box, its data output format (CSV via optional USB interface) is compatible with validated LIMS and electronic lab notebook (ELN) systems used in pharmaceutical and food-grade GMP facilities.

Software & Data Management

The RX-007α operates as a standalone instrument with embedded firmware; no PC connection is required for routine operation. All measurement parameters—including temperature setpoint, unit selection (RI/Brix), and ATC activation—are configurable via intuitive front-panel navigation. Measurement data are stored internally (up to 1,000 records) with timestamp, operator ID (optional), and temperature reading. Optional USB-to-PC connectivity enables batch export of measurement history for statistical process control (SPC) analysis, trend monitoring, and audit-ready documentation. Exported files conform to UTF-8 CSV structure, facilitating direct import into Excel, JMP, or Minitab for capability analysis (Cp/Cpk), ANOVA, or Shewhart charting.

Applications

• Quantification of soluble solids in tea infusions and Camellia sinensis extracts for raw material grading and extraction yield optimization
• In-process monitoring of fermentation broths containing low-concentration polysaccharides (e.g., arabinose, xylose, galactose-rich fractions)
• QC testing of hypo-osmolar oral rehydration solutions and electrolyte-enhanced functional waters
• Batch release verification of botanical tinctures and standardized herbal liquid preparations per USP and Ph. Eur. 2.2.37
• Research applications in food chemistry labs studying Maillard reaction kinetics, where early-stage sugar degradation alters RI at sub-1% concentration levels

FAQ

What is the minimum detectable Brix increment on the RX-007α?

The instrument resolves Brix to 0.001%, with stated accuracy of ±0.005% under ISO-standardized calibration conditions.
Does the RX-007α require external calibration standards for daily use?

A single-point calibration using distilled water (RI = 1.33300 at 20 °C) is recommended before each shift; NIST-traceable sucrose standards (e.g., 1.000% w/w) may be used for verification.
Can the RX-007α measure viscous or turbid samples?

No—it is designed exclusively for clear, low-viscosity liquids; suspended particles or high viscosity (>10 mPa·s) will compromise optical path integrity and measurement repeatability.
Is temperature control mandatory for compliant measurements?

While ATC permits ambient-use operation, Peltier-controlled thermostating is required to meet ISO 2173 reproducibility criteria (±0.00005 RI) across multi-operator workflows.
How is compliance with international refractometry standards documented?

Calibration certificates, ATC validation reports, and measurement uncertainty budgets (k=2) are available upon request and align with EURACHEM/CITAC Guide CG4 and ISO/IEC 17025:2017 clause 7.7 requirements.