ATAGO PAL-34S Portable Digital Ethanol Refractometer (g/100g)

Overview

The ATAGO PAL-34S is a compact, handheld digital refractometer engineered for rapid, on-site quantification of ethanol concentration in aqueous solutions—expressed as mass percent (g/100g). It operates on the principle of critical-angle refractometry: light passing through a sample undergoes refraction at the prism–sample interface, and the resulting critical angle is directly correlated to the solution’s refractive index. Through a pre-calibrated algorithm specific to ethanol–water binary systems, the instrument converts refractive index readings into ethanol concentration values without requiring manual temperature correction. Its built-in Automatic Temperature Compensation (ATC) ensures measurement stability across ambient conditions from 10 °C to 35 °C—a range aligned with typical laboratory, production floor, and field environments where ethanol-containing formulations (e.g., disinfectants, solvents, extraction media) are handled. Designed for routine quality control and process verification—not research-grade metrology—the PAL-34S delivers repeatable, operator-independent results within its specified accuracy envelope.

Key Features

• Direct readout in ethanol concentration (g/100g), eliminating need for conversion tables or external calculation
• Integrated ATC system using thermistor-based real-time compensation, compliant with ISO 21748 guidelines for temperature influence mitigation in refractometric measurements
• Digital LCD display with 0.5% resolution and backlight for low-light conditions
• IP65-rated enclosure—dust-tight and protected against water jets—suitable for industrial hygiene and wet-process environments
• Lightweight (100 g) and ergonomically shaped for single-hand operation and extended use
• No external power supply required: powered by two standard AAA batteries with typical service life exceeding 10,000 measurements

Sample Compatibility & Compliance

The PAL-34S is validated for homogeneous, non-viscous, non-opaque aqueous ethanol solutions—such as pharmaceutical sanitizers, industrial cleaning agents, botanical extraction liquors, and fermentation monitoring samples. It is not intended for use with suspensions, emulsions, high-sugar matrices (>60°Brix), or highly volatile mixtures where evaporation may occur during measurement. While not certified to GLP or GMP standards out-of-the-box, its traceable calibration protocol (using NIST-traceable sucrose standards and ethanol reference solutions) supports alignment with internal QA procedures under ISO/IEC 17025-accredited laboratories. The device complies with IEC 60529 for ingress protection and meets RoHS Directive 2011/65/EU requirements for hazardous substance restriction.

Software & Data Management

The PAL-34S is a standalone, embedded-system instrument with no onboard data logging, Bluetooth, or USB connectivity. All measurements are displayed in real time and must be manually recorded. For integration into structured quality documentation workflows, users may employ standardized paper-based log sheets or import readings into LIMS or ELN platforms via secondary transcription. Calibration verification records—including date, operator ID, standard used, and deviation from nominal value—should be retained per FDA 21 CFR Part 11 guidance when used in regulated manufacturing contexts. ATAGO provides downloadable calibration check protocols and traceable reference material specifications through its global technical support portal.

Applications

• Routine verification of ethanol concentration in EPA-registered disinfectant formulations (e.g., 70% v/v or w/w preparations)
• In-process monitoring of ethanol recovery streams in solvent recycling units
• Batch release testing of ethanol-based hand sanitizers per WHO Formulation I and II specifications
• Field assessment of ethanol content in plant extract tinctures and herbal macerates
• Quick screening of denatured alcohol blends prior to formulation or packaging
• Educational labs demonstrating colligative property relationships between concentration and refractive index

FAQ

Does the PAL-34S measure ethanol by volume (v/v) or by weight (w/w)?
It reports ethanol concentration exclusively as mass percent (g/100g, i.e., w/w), based on factory calibration against gravimetrically prepared ethanol–water standards.
Can it be recalibrated by the user?
Yes—using ATAGO-recommended ethanol reference standards (e.g., 10.0%, 25.0%, and 40.0% w/w); full recalibration requires authorized service software and is not field-performable.
Is temperature stabilization required before measurement?
No—ATC compensates dynamically; however, samples should equilibrate to ambient temperature (within 10–35°C) to avoid thermal shock-induced prism condensation or reading drift.
What maintenance is required?
Daily prism cleaning with lens tissue and distilled water; periodic verification using calibration standard; avoidance of abrasive cleaners or organic solvents that may degrade the acrylic prism coating.
Does it comply with pharmacopoeial methods?
While not cited verbatim in USP , EP 2.2.2, or JP 2.05, its operational principle and performance characteristics align with general refractometric approaches referenced in those chapters for ethanol assay verification.