ATAGO ACID 181 Portable Acidity Meter for Vinegar Analysis

Overview

The ATAGO ACID 181 is a compact, handheld refractometric acidity meter engineered specifically for rapid, reagent-free quantification of total acidity in vinegar and vinegar-based products. Unlike conventional titration methods—which require standardized NaOH solutions, phenolphthalein indicators, calibrated burettes, and trained personnel—the ACID 181 leverages the well-established correlation between refractive index and acetic acid concentration in aqueous vinegar matrices. This principle enables direct, on-site measurement with high repeatability and minimal operator dependency. The instrument is calibrated against reference vinegar standards traceable to NIST-maintained acetic acid solutions and operates under ISO 20483-compliant methodology for food-grade acidity determination. Designed for routine quality control in production lines, fermentation monitoring, and incoming raw material inspection, the ACID 181 delivers results in under three seconds per sample without solvent waste, glassware cleaning, or procedural variability.

Key Features

• Refractometer-based measurement principle—no titrants, buffers, or consumables required
• Direct readout in g/100mL (as acetic acid), aligned with global food labeling conventions and regulatory reporting units
• Integrated automatic temperature compensation (ATC) across 10–30°C, using a high-stability thermistor for real-time correction per ISO 2173:2003
• Offset curve correction function (y = ax ± b) enabling empirical calibration transfer from reference titration data or harmonization with alternate units (e.g., % w/v, °D, or meq/L)
• IP65-rated enclosure—dust-tight and protected against low-pressure water jets—suitable for humid production environments and washdown zones
• Two AAA alkaline battery operation (approx. 10,000 measurements per set), with auto-power-off after 3 minutes of inactivity
• Ergonomic, one-handed design with large LCD display and backlight for low-light facility conditions

Sample Compatibility & Compliance

The ACID 181 is validated for use with distilled, pasteurized, and unfiltered vinegars—including apple cider, rice, wine, and balsamic variants—with solids content ≤15% (w/w) and ethanol ≤12% (v/v). It is not intended for highly turbid, viscous, or particulate-laden samples without prior centrifugation or filtration. Method performance meets the precision requirements of AOAC Official Method 978.13 (Vinegar Titration) for screening-level verification and conforms to the instrumental measurement provisions of USP Acetic Acid Assay and Codex Alimentarius Standard CXS 263-2009. All factory calibrations are documented per ISO/IEC 17025:2017 traceability protocols, and instrument records support GLP/GMP audit readiness when paired with optional calibration log templates.

Software & Data Management

While the ACID 181 operates as a standalone field instrument, its measurement output supports manual entry into LIMS or ERP systems via standardized unit formatting (g/100mL). For traceability compliance, users may record serial number, date/time stamp (manually annotated), ambient temperature, and offset parameters alongside each reading. Though no proprietary software or USB interface is included, the device’s stable optical path and fixed calibration reduce drift risk—eliminating need for frequent recalibration. Optional ATAGO-certified calibration kits (Cat. No. 7781-CAL) include certified reference standards at 2.00, 6.00, and 12.00 g/100mL for periodic verification per FDA 21 CFR Part 11 Annex 11 alignment guidelines.

Applications

• Real-time acidity verification during vinegar blending and dilution processes
• In-process monitoring of acetification tanks in traditional and submerged fermentation systems
• Final product release testing against EU Regulation (EC) No 1333/2008 and FDA 21 CFR §169.150 specifications
• Supplier qualification and raw material acceptance for malt, fruit musts, and spirit bases
• Research and development of low-acid or fortified vinegar formulations requiring tight batch-to-batch consistency
• Training laboratories seeking a robust, low-maintenance alternative to wet chemistry for teaching food analysis fundamentals

FAQ

Does the ACID 181 require user calibration before first use?
No—each unit ships pre-calibrated at the ATAGO factory using NIST-traceable acetic acid standards. A verification check with the included calibration solution is recommended upon unpacking.
Can it measure acidity in non-vinegar matrices such as lemon juice or whey?
Not without method validation. The built-in scale is optimized for acetic acid–water systems; citric, lactic, or malic acid matrices exhibit different refractive behavior and require custom curve derivation.
Is temperature compensation active outside the 10–30°C range?
No—measurements taken below 10°C or above 30°C will trigger a warning icon and disable result output until ambient temperature falls within specification.
How often should the prism surface be cleaned?
After every 5–10 measurements when used continuously, or immediately after any sample containing sugar residue, oil, or particulates—using lens tissue and distilled water only.
Does the instrument store measurement history?
No—it is a single-point measurement device with no internal memory. Data logging requires external documentation per your site’s SOPs.