MATER-S28α Sodium Chloride Refractometer with ATC and IP65 Rating

Overview

The MATER-S28α Sodium Chloride Refractometer is a precision handheld optical instrument engineered for rapid, field-deployable quantification of sodium chloride concentration in aqueous brine solutions. It operates on the fundamental principle of critical angle refractometry: light passing from a high-refractive-index prism into a sample undergoes total internal reflection at an angle dependent on the sample’s refractive index, which correlates directly with NaCl mass fraction under controlled conditions. Designed specifically for food processing environments—including pickling operations, seafood preservation, and salt-cured product quality control—the MATER-S28α delivers calibrated NaCl readings across a linear 0.0–28.0% (w/w) range. Its integrated automatic temperature compensation (ATC) system—based on a thermally sensitive bimetallic element—corrects refractive index deviations caused by ambient thermal fluctuations between 10°C and 30°C, ensuring measurement stability without external calibration or manual correction. The device complies with JIS Z 8806:2017 (Refractometric Determination of Soluble Solids) and aligns with ISO 2173:2003 methodology for refractometric analysis of food products.

Key Features

• High-accuracy NaCl scale (0.0–28.0% w/w) with 0.2% minimum division and ±0.2% accuracy within 10–30°C operating range
• Robust ATC mechanism eliminating need for manual temperature correction or recalibration during routine use
• IP65-rated housing (excluding eyepiece assembly), providing full protection against dust ingress and resistance to low-pressure water jets—suitable for humid, saline, or washdown-intensive production areas
• Chemically resistant prism and body materials engineered for long-term exposure to acidic brines and high-salinity environments
• Compact ergonomic design (3.2 × 3.4 × 20.3 cm; 105 g) optimized for one-handed operation and portability across processing lines or cold storage zones
• Dual illumination compatibility: functions effectively under natural daylight (with included RE-2391-59M daylight plate) or ambient artificial lighting

Sample Compatibility & Compliance

The MATER-S28α is validated for direct measurement of clear to mildly turbid aqueous NaCl solutions typical in food-grade brining applications—e.g., pickle brines, fish curing solutions, and fermented vegetable marinades. It is not intended for non-aqueous solvents, highly viscous suspensions, or emulsions. For viscous samples, the optional RE-2391-50M micro-sample prism cover enables precise application of minimal volume (≈0.3 mL) while minimizing evaporation and surface tension effects. The instrument meets IP65 per IEC 60529 for environmental robustness and supports traceable quality assurance workflows compliant with HACCP, ISO 22000, and FDA Food Code §3-202.12 requirements for critical control point monitoring in food manufacturing. Calibration verification may be performed using certified NaCl reference standards traceable to NIST SRM 999b or equivalent national metrology institutes.

Software & Data Management

As a fully analog optical instrument, the MATER-S28α requires no firmware, battery, or digital interface—ensuring operational continuity in environments where electromagnetic interference, power instability, or data security protocols restrict electronic devices. All measurements are read visually through the ocular lens against a fixed engraved scale, eliminating software validation burdens associated with 21 CFR Part 11 compliance. For laboratory integration, users may document readings manually in paper-based QC logs or digitize results via LIMS-compatible entry forms. Optional accessories—including calibration certificates issued by the authorized Japanese distributor—support audit readiness under GLP and GMP frameworks requiring instrument qualification records (IQ/OQ documentation available upon request).

Applications

• Real-time brine concentration monitoring during vegetable fermentation (e.g., kimchi, sauerkraut, olives)
• Quality verification of salt-cured seafood (salted mackerel, dried squid, anchovy paste base solutions)
• In-process control of salting baths in meat and poultry processing facilities
• Raw material screening of commercial brine concentrates prior to dilution and blending
• Sanitation verification of salt-based disinfectant solutions used in food contact surface cleaning
• Educational demonstration of colligative properties and refractive index–concentration relationships in food science curricula

FAQ

Does the MATER-S28α require periodic recalibration?
No routine recalibration is required; however, verification with a certified 10.0% or 20.0% NaCl standard solution is recommended before each shift or after exposure to extreme temperature gradients.
Can it measure potassium chloride or other salt solutions?
No—it is optically calibrated exclusively for NaCl mass fraction. Use of alternative salts introduces systematic bias due to differing partial molar refractions and is not supported by the scale.
Is the eyepiece waterproof?
The IP65 rating applies to the main body and prism assembly only; the eyepiece is not sealed and must be protected from direct water spray or submersion.
What is the expected service life of the prism surface?
With proper cleaning using distilled water and soft lens tissue (no abrasive solvents), the borosilicate glass prism maintains optical integrity for ≥5 years under typical food plant usage conditions.
Is the RE-2391-50M prism cover compatible with all MASTER-series refractometers?
Yes—this accessory is standardized across the MASTER line, including MATER-S28α, PAL-1, and RX-5000α models, enabling cross-platform workflow consistency.