ATAGO RX-007α Desktop Digital Refractometer

Overview

The ATAGO RX-007α is a high-precision benchtop digital refractometer engineered for accurate, repeatable measurement of low-concentration aqueous solutions in quality control and R&D environments. It operates on the principle of total internal reflection at the prism-sample interface, where the critical angle of refraction is directly correlated to the sample’s refractive index—and thus its solute concentration. Unlike handheld or analog units, the RX-007α integrates a temperature-compensated optical system with a high-resolution CCD sensor and embedded microprocessor, enabling automatic calculation and display of concentration values in real time. Its design targets applications requiring sub-0.001 % resolution in dilute systems—such as pharmaceutical buffer preparation, semiconductor cleaning solution verification, ultrapure water conductivity correlation, and low-Brix functional beverage formulations. The instrument does not incorporate active temperature regulation; instead, it relies on ambient thermal equilibrium and built-in temperature sensing (±0.5 °C accuracy) to apply standard refractive index correction algorithms per JIS K 0063 and ISO 21748.

Key Features

• Precision optical system with sapphire-coated measuring prism for long-term scratch resistance and chemical inertness
• Digital LCD display with 0.001 % resolution and auto-zero function for baseline calibration stability
• Internal temperature sensor with real-time compensation, compliant with JIS K 0063 reference methodology
• Benchtop ergonomics: stable base, integrated sample stage, and easy-access prism cleaning port
• Non-destructive, single-drop measurement mode (minimum sample volume: 0.3 mL)
• Factory-calibrated using NIST-traceable sucrose standards; user calibration supported via two-point adjustment
• Robust architecture with IP20-rated enclosure suitable for ISO Class 7 cleanroom-adjacent lab environments

Sample Compatibility & Compliance

The RX-007α is validated for transparent, non-viscous, non-scattering aqueous solutions with refractive index deviations ≤ 0.0005 RIU from pure water. Compatible matrices include saline buffers (e.g., PBS, Tris-HCl), dilute acid/base titrants, ethanol–water mixtures below 5 % v/v, and low-conductivity rinse solutions used in wafer fabrication. It is not intended for turbid suspensions, emulsions, high-viscosity polymers (>10 mPa·s), or strongly absorbing media (e.g., concentrated dyes). Regulatory alignment includes conformity with CE marking requirements, adherence to JIS K 0063 (Refractometric Determination of Concentration), and technical compatibility with ISO 21748 (Guidance for the Estimation of Measurement Uncertainty in Repeated Measurements). While not FDA 21 CFR Part 11–certified out-of-the-box, audit-ready operation is achievable when deployed within documented GLP/GMP workflows that include defined calibration frequency, operator training records, and electronic logbook integration.

Software & Data Management

The RX-007α operates as a standalone instrument with no proprietary software dependency. All measurements are displayed locally and may be manually recorded. For traceable data capture, optional RS-232 output (with included cable) enables ASCII-formatted data streaming to external terminals, LIMS interfaces, or Excel-compatible acquisition tools. Output includes timestamp (if host system provides), measured value, unit identifier (%), and sensed temperature. No onboard memory or password protection is provided; data integrity relies on procedural controls—consistent with ISO/IEC 17025 Clause 7.5 requirements for equipment-generated results. Firmware updates are performed exclusively by authorized ATAGO service centers.

Applications

• Pharmaceutical: Verification of low-concentration excipient solutions (e.g., mannitol, glycine) prior to lyophilization
• Semiconductor manufacturing: Monitoring deionized water purity and trace IPA concentrations in photoresist removal baths
• Food & Beverage R&D: Quantifying subtle sugar or organic acid shifts in functional waters and electrolyte drinks
• Academic research: Calibration reference for UV-Vis absorbance–concentration correlations in dilute model systems
• Environmental testing labs: Cross-validation of conductivity-derived TDS estimates in freshwater effluent streams

FAQ

Does the RX-007α support automatic temperature control?
No. It features passive thermal equilibration and real-time temperature sensing (±0.5 °C), but lacks Peltier or fluid-circulation temperature regulation.
What is the minimum detectable concentration change?
The instrument resolves increments of 0.001 % under stable ambient conditions and proper prism hydration.
Can it measure ethanol–water solutions above 5 % v/v?
No. Its calibrated range is strictly 0.000–5.000 % on a Brix-equivalent scale; extrapolation beyond this introduces nonlinearity and increased uncertainty.
Is user calibration possible without factory service?
Yes—two-point calibration using certified reference standards (e.g., distilled water and 2.000 % NaCl solution) is supported via front-panel menu.
Does it comply with ISO/IEC 17025 requirements for accredited testing labs?
It meets the metrological requirements for instrumentation when operated within a validated method, including documented calibration, environmental monitoring, and operator competency assessment.