ATAGO PAL-BX/ACID and PAL-Easy/ACID Series Portable Refractometric Brix & Acidity Meters

Overview

The ATAGO PAL-BX/ACID and PAL-Easy/ACID series are handheld refractometric instruments engineered for rapid, on-site quantification of soluble solids content (expressed as Brix %) in aqueous solutions—primarily fruit juices, beverages, and food processing streams. These meters operate on the principle of critical-angle refractometry: light passing through a sample undergoes refraction proportional to its solute concentration, which is converted into a digital Brix reading via an embedded prism sensor and temperature-compensated optical algorithm. While marketed with “acidity” in the model name, these units do not perform direct pH or titratable acidity measurement; rather, they estimate apparent acidity indirectly via empirical correlation with Brix and known juice composition profiles—common practice in horticultural quality control where Brix:acid ratio serves as a maturity index. Designed for field use, the series integrates a robust aluminum housing, automatic temperature compensation (ATC) across 10–40 °C, and a single-button operation interface optimized for repetitive measurements under variable ambient conditions.

Key Features

• Optical refractometer core with sapphire-coated prism for scratch resistance and long-term calibration stability
• Integrated ATC (Automatic Temperature Compensation) compliant with JIS K 0067 and ISO 2173 standards
• Real-time digital display with 0.1% Brix resolution and user-accessible zero calibration function
• Battery-powered operation (2 × AAA batteries, ~10,000 measurements per set) enabling deployment in orchards, packing houses, and cold storage facilities
• IP65-rated enclosure for dust and water jet resistance—suitable for humid or wet processing environments
• Factory-calibrated with NIST-traceable sucrose reference solutions; optional recalibration kit available for routine QC verification

Sample Compatibility & Compliance

These meters accept liquid samples requiring minimal preparation: clear or mildly turbid juices (e.g., apple, orange, grape), syrups, soft drink concentrates, and fermented musts—provided particulates are filtered to avoid prism fouling. Viscous or highly pulpy samples (e.g., unfiltered tomato paste) require centrifugation or fine filtration prior to analysis. The PAL-BX/ACID series is not intended for non-aqueous solvents, high-alcohol solutions (>15% v/v), or strongly acidic/alkaline media outside pH 3–11, as these may degrade the prism coating or distort refractive index response. Regulatory alignment includes CE marking for EMC and safety, conformance to Japanese Industrial Standard JIS K 0067 (refractometric determination of soluble solids), and compatibility with ISO 2173 for fruit juice analysis workflows. While not FDA 21 CFR Part 11 compliant out-of-the-box (lacking audit trail or electronic signature functionality), raw Brix data may be documented manually or exported via optional RS-232 interface for inclusion in GLP/GMP-compliant quality records.

Software & Data Management

The PAL-BX/ACID and PAL-Easy/ACID models are standalone instruments with no onboard memory or Bluetooth/Wi-Fi connectivity. All measurements are displayed in real time and must be recorded externally. An optional RS-232 cable (ATAGO part no. PAL-COM) enables serial output to a PC or PLC for automated logging into LIMS or Excel-based QA databases. No proprietary software is required; ASCII-formatted output follows standard carriage-return line-feed protocol at 9600 baud. For traceability, users are advised to log instrument ID, calibration date, operator initials, ambient temperature, and sample identification alongside each Brix value—practices aligned with ISO/IEC 17025 documentation requirements for testing laboratories.

Applications

• Harvest timing decisions based on Brix thresholds in commercial orchards (e.g., ≥12.5% for ‘Fuji’ apples, ≥18.0% for ‘Thompson Seedless’ grapes)
• In-line quality screening of juice blends during beverage manufacturing to ensure batch consistency
• Ripeness assessment of intact fruit using ATAGO’s companion PAL-HIKARi Ripeness meter (a separate NIR-based device)—note: PAL-BX/ACID units themselves do not perform non-destructive ripeness evaluation
• QC verification of sugar concentration in syrup preparations for confectionery and dairy applications
• Educational use in food science labs for teaching fundamental principles of solution density, refractive index, and colligative properties

FAQ

Do these meters measure actual titratable acidity (TA) or pH?
No. They report Brix only. Apparent acidity values labeled on certain models derive from pre-programmed Brix–acid correlation tables—not electrochemical or potentiometric measurement.
Can I measure hot or frozen samples directly?
Samples must be at equilibrium with ambient temperature (10–40 °C). Hot liquids risk prism damage and thermal drift; frozen samples must be fully thawed and homogenized before analysis.
How often should I calibrate?
Perform zero calibration with distilled water before each measurement session. Full span calibration using 10.0% or 30.0% sucrose standard is recommended daily in high-precision environments or after exposure to extreme temperatures.
Is the prism resistant to citric or malic acid corrosion?
The sapphire-coated prism resists mild organic acids typical in fruit juices but is not suitable for prolonged contact with undiluted acetic or phosphoric acid solutions.
Does “PAL-Easy/ACID” imply dual-parameter capability?
No. Each unit measures Brix exclusively. “ACID” denotes application context—not analytical functionality. Dual-parameter devices (e.g., Brix + pH) require separate instrumentation.