ATAGO DR-M2 Desktop Multi-Wavelength Abbe Refractometer
| Brand | ATAGO |
|---|---|
| Origin | Japan |
| Model | DR-M2 |
| Product Type | Benchtop Refractometer |
| Temperature Control | Yes |
| Digital Display | Yes |
| Refractive Index Range | 1.2743–1.6840 |
| Measurement Accuracy | ±0.0002 |
Overview
The ATAGO DR-M2 is a high-precision benchtop Abbe refractometer engineered for rigorous optical characterization of transparent and translucent liquids across multiple wavelengths. Unlike conventional single-wavelength instruments, the DR-M2 integrates a motorized wavelength selector and calibrated interference filters to enable spectral refractive index measurements at discrete, traceable wavelengths—including 589.3 nm (Na-D line), 486.1 nm (H-beta), 587.6 nm (He-d), and 656.3 nm (H-alpha)—supporting dispersion analysis (dn/dλ) and Cauchy or Sellmeier coefficient derivation. Its optical architecture follows the classical Abbe principle: collimated light passes through a sample sandwiched between two precision-ground prisms; the critical angle of total internal reflection is detected via a high-resolution CCD linear array, enabling direct digital conversion of the shadow boundary into refractive index values. Designed for metrology-grade repeatability in QC labs, R&D facilities, and optical material certification workflows, the DR-M2 meets fundamental requirements for ISO/IEC 17025-compliant refractive index calibration and supports traceability to NIST-traceable reference standards.
Key Features
- Multi-wavelength capability with selectable standard spectral lines (486.1, 587.6, 589.3, 656.3 nm) for full dispersion profiling
- Integrated Peltier temperature control system (range: 10–50 °C, stability: ±0.1 °C) ensuring thermal equilibrium during measurement
- Digital refractive index readout with 0.0001 resolution and ±0.0002 accuracy (at 20 °C, 589.3 nm)
- Automated critical angle detection using linear CCD sensor and real-time image processing algorithm
- Benchtop form factor with rigid aluminum alloy chassis and anti-vibration base mount for stable optical alignment
- Compliance with JIS K 0061 and ASTM D1218 standards for liquid refractive index determination
Sample Compatibility & Compliance
The DR-M2 accommodates samples with refractive indices from 1.2743 to 1.6840—covering common organic solvents (e.g., acetone, toluene), polymer precursors, optical resins, specialty oils, and high-index immersion fluids used in microscopy and lithography. Sample volume requirement is ≤0.2 mL per measurement; compatibility extends to mildly corrosive liquids (e.g., halogenated hydrocarbons) when used with optional sapphire prism protection kits. All optical path components—including main prism, illuminator lens, and detector window—are manufactured from fused silica and hardened optical glass to minimize chromatic drift and thermal expansion error. The instrument conforms to IEC 61000-4 electromagnetic immunity standards and carries CE marking for use within the European Economic Area. Calibration verification procedures align with ISO 17025 clause 6.6 and support GLP audit documentation requirements.
Software & Data Management
The DR-M2 operates via ATAGO’s proprietary PC-based software suite (Windows 10/11 compatible), which enables full instrument control, multi-point temperature ramping, spectral data acquisition, and dispersion curve fitting. Raw measurement data—including wavelength, RI value, temperature, timestamp, and operator ID—is exported in CSV or XML format for integration into LIMS environments. Audit trail functionality records all parameter changes, calibration events, and user logins in accordance with FDA 21 CFR Part 11 requirements. Optional software modules support automated calculation of Abbe number (vd), partial dispersion ratios (e.g., θgF), and refractive index interpolation at non-standard wavelengths using third-order Sellmeier equations.
Applications
- Optical glass and lens material certification (e.g., BK7, SF11, F2, LaK9)
- Quality control of monomers, prepolymers, and UV-curable resins in photolithography
- Refractive index mapping of gradient-index (GRIN) optical fibers and waveguides
- Characterization of immersion oils for super-resolution microscopy (e.g., oil immersion objectives requiring n = 1.518 @ 589 nm)
- Development and validation of high-index antireflection coatings and thin-film interference stacks
- Thermo-optic coefficient (dn/dT) measurement via synchronized temperature sweeps
FAQ
Does the DR-M2 support custom wavelength selection beyond the four factory-installed filters?
No—the DR-M2 uses fixed interference filters certified for metrological stability; custom wavelengths require factory recalibration and are not field-serviceable.
Can the instrument measure solid samples?
Not directly; the DR-M2 is configured for liquid-phase measurement only. Solid samples require contact liquid matching and specialized prism accessories not included with standard configuration.
Is NIST-traceable calibration certificate provided with shipment?
Yes—a manufacturer-issued calibration certificate traceable to NIST SRM 1484 (refractive index standards) is included, with uncertainty budget documented per ISO/IEC 17025 Annex A.
What maintenance is required for long-term optical accuracy?
Annual verification using ATAGO-certified reference liquids (e.g., bromonaphthalene, carbon disulfide) is recommended; prism cleaning must be performed with spectroscopic-grade methanol and lint-free optical tissue.
Is remote operation supported over Ethernet or USB?
Yes—USB 2.0 interface is standard; optional Ethernet adapter enables TCP/IP communication for integration into automated lab networks and SCADA systems.
