ATAGO PAL-Hypochlorous Acid Handheld Refractometer

Overview

The ATAGO PAL-Hypochlorous Acid Handheld Refractometer is a dedicated optical instrument engineered for rapid, on-site quantification of hypochlorous acid (HOCl) concentration in aqueous disinfectant solutions. Unlike generic refractometers, this model employs a custom-calibrated optical dispersion algorithm optimized specifically for the refractive index–concentration relationship of stabilized HOCl solutions within the physiologically and industrially relevant range of 50–550 ppm. Its operation is based on the principle of total internal reflection at the prism–sample interface: incident light undergoes angular deviation proportional to the solution’s refractive index, which correlates directly with HOCl mass concentration under controlled temperature conditions. Integrated Peltier-assisted temperature control ensures measurement stability across ambient fluctuations (10–40 °C), minimizing thermal drift and enabling reproducible results without external water baths or calibration recalibration between samples. Designed for frontline hygiene validation, it supports real-time verification of disinfectant potency prior to application—critical for compliance with infection control protocols in healthcare, food service, and public infrastructure settings.

Key Features

• Titanium-coated sapphire prism surface: Resists corrosion and etching from acidic HOCl solutions (pH 5.0–6.5), ensuring long-term optical fidelity and mechanical durability.
• Integrated thermoelectric (Peltier) temperature regulation: Maintains prism surface at 25 °C ±0.2 °C during measurement, eliminating manual temperature correction and improving inter-laboratory comparability.
• Three-second measurement cycle: Requires only 0.3 mL sample volume; automatic endpoint detection prevents user-induced timing errors.
• IP65-rated enclosure: Dust-tight and protected against low-pressure water jets—suitable for use in wet environments including cleaning stations, production floors, and mobile sanitation units.
• GLP-compliant data logging: Stores up to 1,000 measurement records with timestamp, temperature reading, and operator ID (via optional USB interface and ATAGO Data Manager software).
• Battery-powered portability: Operates continuously for >10,000 measurements per set of AAA alkaline cells; auto-power-off after 3 minutes of inactivity.

Sample Compatibility & Compliance

The PAL-Hypochlorous Acid refractometer is validated for use with clear, non-turbid, non-viscous aqueous HOCl solutions containing ≤0.1% stabilizers (e.g., sodium chloride, phosphate buffers) and free from suspended solids or emulsified oils. It is incompatible with chlorine dioxide, sodium hypochlorite (NaOCl), or mixed oxidant solutions. Measurements adhere to ASTM D7812–19 (Standard Practice for Determination of Active Chlorine Species in Disinfectant Solutions by Refractometric Methods) and support internal quality assurance aligned with ISO 13695:2021 (Disinfectants – Quantitative suspension test for chemical disinfectants). While not a primary method for regulatory submission, its results are traceable to NIST-traceable refractive index standards and serve as a rapid screening tool compliant with WHO Guidelines on Hand Hygiene in Health Care (2009) and CDC Environmental Infection Control Recommendations (2023).

Software & Data Management

Data export is supported via USB-C connection to Windows-based systems running ATAGO Data Manager v3.2 or later. The software enables batch export to CSV/Excel, statistical analysis (mean, SD, CV%), trend charting over time, and generation of audit-ready reports compliant with FDA 21 CFR Part 11 requirements—including electronic signatures, audit trails, and user-access controls. All stored measurements retain full metadata: date/time stamp, ambient temperature, prism temperature, measured ppm value, and operator code. Firmware updates are delivered through the same interface and include calibration certificate revision history and enhanced outlier detection algorithms.

Applications

• Validation of HOCl concentration in hospital-grade disinfectant sprays prior to environmental surface disinfection (e.g., door handles, bed rails, countertops).
• Quality control during in-house preparation of electrolyzed water (EW) in food processing facilities, ensuring consistent antimicrobial efficacy per USDA-FSIS Directive 7120.1.
• Field verification of commercial HOCl products used in school and municipal sanitation programs, supporting documentation for state-level health department reporting.
• Research laboratories studying HOCl stability under varying storage conditions (light exposure, container material, pH drift), where rapid serial sampling is required.
• GMP-regulated cleanroom maintenance teams verifying disinfectant concentration before aseptic zone entry, fulfilling Annex 1 (EU GMP) section 8.32 requirements for disinfectant monitoring.

FAQ

Does this instrument measure total chlorine or free chlorine?
No. The PAL-Hypochlorous Acid refractometer is optically calibrated exclusively for molecular hypochlorous acid (HOCl) in low-pH, stabilized aqueous solutions. It does not respond to hypochlorite ion (OCl⁻), chlorine gas (Cl₂), or chloramines.
Can I use it with sodium hypochlorite (bleach) solutions?
No. Sodium hypochlorite solutions operate at high pH (11–13), where HOCl constitutes <5% of total chlorine. This instrument will yield inaccurate and non-linear readings outside its validated matrix.
Is temperature compensation automatic?
Yes. The built-in Peltier element actively regulates prism temperature to 25 °C; no manual input or external thermostat is required.
How often does it require factory recalibration?
ATAGO recommends annual recalibration against certified HOCl reference standards (NIST-traceable, matrix-matched). Field verification using 100 ppm and 400 ppm check standards is advised before each daily shift.
Does it comply with FDA 21 CFR Part 11 for electronic records?
The device itself is not Part 11–certified, but when used with ATAGO Data Manager v3.2+ and configured with role-based access and audit trail enabled, the complete system meets predicate rule requirements for electronic record integrity and authenticity.