ATAGO PAL-40S Sodium Hydroxide (NaOH) Concentration Meter
| Brand | ATAGO |
|---|---|
| Origin | Japan |
| Model | PAL-40S |
| Measurement Range | 0.0–38.0% NaOH (w/w) |
| Resolution | 0.1% NaOH |
| Accuracy | ±0.2% NaOH |
| Temperature Resolution | 0.1°C |
| Temperature Accuracy | ±1.0°C |
| Sample Volume | 0.3 mL |
| Measurement Time | 3 seconds |
| Operating Temperature | 10–35°C (with Automatic Temperature Compensation, ATC) |
| Protection Rating | IP65 |
| Power Supply | 2 × AAA batteries |
| Dimensions | 55(W) × 31(D) × 109(H) mm |
| Weight | 100 g (body only) |
Overview
The ATAGO PAL-40S Sodium Hydroxide (NaOH) Concentration Meter is a handheld, optical refractometer engineered for rapid, field-deployable quantification of aqueous sodium hydroxide solutions across industrial process control, quality assurance, and laboratory settings. Unlike generic Brix refractometers, the PAL-40S employs a custom-calibrated optical dispersion algorithm specifically validated against certified NaOH reference standards—enabling direct readout in mass percent (w/w %), not sugar-equivalent Brix units. Its measurement principle relies on the linear correlation between solution refractive index and NaOH concentration at controlled temperature, with built-in automatic temperature compensation (ATC) referencing the standard ISO 21748:2017 methodology for refractive index correction. Designed for routine use in caustic environments—including chemical manufacturing, pulp & paper bleaching, water treatment dosing, and electroplating bath management—the instrument delivers traceable, repeatable results without requiring reagent addition, dilution, or titration.
Key Features
- Direct NaOH concentration readout from 0.0 to 38.0% (w/w), eliminating manual conversion from Brix or density tables
- High-resolution optical sensor with 0.1% resolution and ±0.2% accuracy (at 20°C, verified per ATAGO calibration protocol)
- Integrated ATC system (10–35°C operating range) using a high-stability thermistor aligned with ISO 21748:2017 temperature-correction curves
- Rugged, IP65-rated housing resistant to dust ingress and low-pressure water jets—suitable for wet industrial floors, tank farms, and outdoor dosing stations
- Minimal sample requirement of just 0.3 mL, enabling non-destructive testing of small-volume or high-value process streams
- Three-second measurement cycle with auto-hold function, optimized for high-throughput batch verification or continuous line monitoring
- Lightweight (100 g) ergonomic design with rubberized grip and large LCD display readable under ambient plant lighting
Sample Compatibility & Compliance
The PAL-40S is validated exclusively for homogeneous, clarified aqueous NaOH solutions free of suspended solids, oils, or emulsified organics that may scatter light and compromise refractive index fidelity. It is not intended for use with molten NaOH, mixed alkali systems (e.g., NaOH + Na₂CO₃), or highly viscous slurries. The device complies with IEC 60529 for IP65 enclosure rating and meets CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU) and low-voltage safety (LVD Directive 2014/35/EU). While not a GLP/GMP-certified instrument per se, its documented calibration traceability to NIST-traceable NaOH standards supports data integrity in regulated environments where process analytical technology (PAT) principles apply.
Software & Data Management
The PAL-40S operates as a standalone, battery-powered meter with no onboard data logging or connectivity. All measurements are displayed in real time on the integrated LCD screen; no external software, drivers, or cloud integration is required. For audit-ready documentation, users may manually record readings alongside batch identifiers, operator ID, and environmental conditions. When deployed within a broader QA/QC framework, the PAL-40S serves as a primary point-of-use verification tool—complementing centralized lab titrations (e.g., ASTM D1172 or ISO 6353-2) by providing immediate feedback for corrective action prior to final product release.
Applications
- Real-time verification of NaOH stock solution preparation in chemical synthesis and catalyst activation
- In-line concentration checks during caustic washing stages in food processing equipment sanitation protocols
- Monitoring of lye concentration in traditional soap saponification processes
- Quality gate inspection of incoming NaOH deliveries at receiving docks
- Routine maintenance of alkaline cleaning solutions in semiconductor wafer fabrication cleanrooms
- Field validation of neutralization endpoint stability in wastewater pH adjustment systems
FAQ
Does the PAL-40S require calibration with standard NaOH solutions before each use?
No—factory calibration is stable for typical industrial use. ATAGO recommends verification against a certified 10.0% or 25.0% NaOH reference standard once per shift when used in critical control points.
Can the PAL-40S measure sodium hydroxide in the presence of sodium chloride or other salts?
No. Dissolved ionic impurities significantly alter refractive index response. The instrument assumes binary NaOH–water composition; multi-solute systems require alternative methods such as ion chromatography or potentiometric titration.
Is the prism surface chemically resistant to concentrated NaOH?
Yes—the sapphire-coated prism is rated for repeated exposure to ≤50% NaOH at ambient temperatures and can be safely rinsed with deionized water after each measurement.
What is the expected service life of the AAA batteries under normal usage?
Approximately 10,000 measurements (or ~12 months of daily use), based on ATAGO’s internal power consumption testing at 25°C.
Does the PAL-40S comply with FDA 21 CFR Part 11 for electronic records?
No—it generates no electronic records. Its analog optical measurement pathway and lack of data storage preclude Part 11 applicability; it functions as a manual measurement aid consistent with traditional glass hydrometers or titration burettes.
