ATAGO RX-007α Low-Concentration Precision Digital Refractometer

Overview

The ATAGO RX-007α is a high-precision benchtop digital refractometer engineered specifically for quantitative analysis of low-concentration aqueous solutions where conventional refractometers lack sufficient resolution and thermal stability. Operating on the principle of critical angle measurement of total internal reflection, the instrument determines refractive index (n_D) with sub-micro-level resolution—enabling trace-level quantification of solutes such as sucrose, glycols, surfactants, corrosion inhibitors, and tea polyphenol extracts. Its optical architecture integrates a temperature-stabilized prism assembly and a high-stability LED light source coupled to a precision photodiode array, ensuring repeatable measurements under controlled thermal conditions. Designed for laboratories requiring compliance with ISO 21542, ASTM D1218, and USP , the RX-007α delivers metrological rigor essential for QC/QA workflows in beverage R&D, surface treatment formulation, and functional ingredient validation.

Key Features

• Ultra-high-resolution refractive index measurement: 0.000001 n_D resolution with ±0.000010 accuracy—optimized for samples with Brix ≤ 5.000%
• Active Automatic Temperature Compensation (ATC): Dual-mode thermoregulation maintains sample temperature within ±0.05°C across ambient ranges from 15°C to 30°C, eliminating manual calibration drift
• Corrosion-resistant sample well fabricated from medical-grade SUS316 stainless steel—compatible with acidic, alkaline, and surfactant-laden formulations
• Optical glass prism with anti-scratch coating and validated long-term refractive stability per JIS Z 8011
• Dual-parameter real-time display: simultaneous n_D and Brix values with user-selectable decimal places (up to three for Brix)
• RS-232C serial interface for direct integration into LIMS or ELN platforms; supports GLP-compliant audit trail generation when paired with compliant software
• Energy-efficient design: 65 VA max power draw, CE and RoHS certified, suitable for continuous operation in ISO/IEC 17025-accredited labs

Sample Compatibility & Compliance

The RX-007α is validated for use with transparent, non-turbid, water-miscible liquids—including green tea infusions, low-sugar RTD beverages, anionic/cationic surfactant solutions, water-based rust inhibitors, and mild detergent concentrates. It excludes opaque suspensions, emulsions, or highly viscous fluids (>100 mPa·s) due to optical path constraints. All measurement protocols align with ISO 21542:2021 (Refractometry — General principles), ASTM D1218-22 (Standard Test Method for Refractive Index of Hydrocarbon Liquids), and FDA-recommended practices for concentration verification in food contact substance testing. The instrument’s ATC performance has been verified against NIST-traceable thermostatic reference standards across its full operational ambient range.

Software & Data Management

While the RX-007α operates as a standalone instrument, its RS-232C port enables bidirectional communication with third-party data acquisition systems. Users may configure up to 30 custom calibration curves via PC-based setup utility (ATAGO PC-Link software, sold separately), supporting non-linear Brix-to-concentration conversions for proprietary formulations. Exported datasets include timestamp, ambient temperature, sample ID, n_D, Brix, and instrument serial number—structured for CSV ingestion into statistical process control (SPC) tools. When deployed in regulated environments, the system supports 21 CFR Part 11-compliant electronic signatures and audit logs when integrated with validated laboratory informatics platforms.

Applications

• Quality control of ready-to-drink (RTD) tea and herbal infusions where Brix deviations > ±0.005% impact flavor consistency and shelf-life modeling
• Formulation development of low-concentration surfactant blends used in semiconductor wafer cleaning and metalworking fluid concentrates
• Verification of dilution accuracy in water-based corrosion inhibitor batches prior to field deployment in HVAC or industrial cooling circuits
• Academic research in colloidal chemistry involving critical micelle concentration (CMC) determination via refractive index titration
• Raw material screening for natural sweeteners (e.g., stevia glycoside extracts) where conventional Brix scales saturate below 0.5% w/w
• Regulatory submission support for food additive dossiers requiring documented refractive index traceability per EFSA Guidance on Food Enzymes

FAQ

What sample volume is required for a valid measurement?
A minimum of 0.3 mL is sufficient to cover the prism surface; excess liquid is automatically drained via gravity-assisted channeling.
Can the RX-007α measure ethanol–water mixtures?
Yes—within its specified n_D range—but only for concentrations yielding refractive indices between 1.330150 and 1.341500; higher ethanol fractions fall outside calibration scope.
Is calibration traceable to national standards?
Factory calibration uses NIST-traceable sucrose reference solutions (SRM 84d); users may perform verification with ATAGO-certified calibration standards (Cat. No. 2521-00).