ATAGO PAL-102S Handheld Coolant Refractometer
| Brand | ATAGO |
|---|---|
| Origin | Japan |
| Product Type | Handheld Refractometer |
| Model | PAL-102S |
| Measurement Range | 0.0–70.0% (w/w) coolant concentration |
| Accuracy | ±0.2% |
| Digital Display | Yes |
| Temperature Compensation | None |
| Compliance | ISO 21748, JIS K 0061, ASTM D1152 (for refractive index-based concentration estimation) |
Overview
The ATAGO PAL-102S Handheld Coolant Refractometer is a precision optical instrument engineered for rapid, on-site determination of aqueous cutting fluid concentration in metalworking environments. It operates on the principle of critical angle refractometry: incident light passes through a sapphire prism in contact with the coolant sample, and the resulting refraction angle—directly correlated to the solution’s refractive index—is converted into a mass concentration value (% w/w) using a pre-calibrated algorithm optimized for common water-soluble coolants (e.g., soluble oils, semi-synthetics, and synthetics). Designed for industrial shop-floor use, the PAL-102S eliminates reliance on time-consuming titration or density-based methods, enabling real-time process control without laboratory infrastructure. Its compact form factor, single-button operation, and immediate digital readout support high-frequency monitoring required for maintaining optimal lubricity, cooling efficiency, and corrosion inhibition in CNC machining, grinding, milling, and turning operations.
Key Features
- Optical system featuring a high-stability sapphire prism with anti-scratch coating for long-term measurement repeatability under workshop conditions.
- Digital LCD display with automatic backlighting for legibility in low-light machine shop environments.
- Single-point calibration using distilled water (0.0%) prior to each measurement session—no external calibration solutions required.
- Battery-powered operation (2 × AAA batteries, included) supporting >5,000 measurements per set; auto-power-off after 3 minutes of inactivity.
- IP65-rated housing resistant to coolant splashes, metal chips, and ambient shop dust.
- No temperature control unit; incorporates built-in automatic temperature compensation (ATC) based on a thermistor sensor (range: 10–40 °C), referenced to 20 °C standard per ISO 21748.
Sample Compatibility & Compliance
The PAL-102S is validated for use with conventional water-miscible metalworking fluids, including emulsifiable oils, micro-emulsions, and fully synthetic coolants. It is not intended for non-aqueous fluids (e.g., neat oils), glycol-based antifreezes, or highly viscous concentrates (>500 mPa·s). Sample volume requirement is ≤0.3 mL; surface tension and volatility are accommodated via optimized prism geometry and rapid measurement cycle (<3 seconds). The instrument complies with ISO 21748 (guidance on reproducibility of refractometric measurements), JIS K 0061 (Japanese Industrial Standard for refractometers), and ASTM D1152 (standard test method for refractive index of industrial chemicals), ensuring traceability in quality assurance workflows. While not FDA 21 CFR Part 11 compliant (as it lacks audit trail functionality), its measurement records may be manually documented in GLP/GMP-aligned logbooks for internal process verification.
Software & Data Management
The PAL-102S is a standalone, embedded-system device with no Bluetooth, USB, or cloud connectivity. All measurement data remain local to the unit and are not stored or exportable. For integration into digital quality management systems (QMS), users may manually record results—including timestamp, operator ID, machine ID, and batch number—into structured Excel templates or LIMS-compatible forms. ATAGO provides optional PC software (Refractometer Manager™, sold separately) compatible with PAL series instruments that supports CSV export, statistical process control (SPC) charting, and calibration history tracking when used with data-enabled models (e.g., PAL-α); however, PAL-102S does not interface with this software due to absence of serial output.
Applications
- Routine concentration verification during coolant tank replenishment and top-up procedures.
- Pre-shift validation of mixed coolant solutions prior to machine startup.
- Troubleshooting of poor surface finish, excessive tool wear, or microbial growth linked to out-of-spec concentration.
- Supporting preventive maintenance logs required by OEM equipment manufacturers (e.g., Fanuc, DMG Mori, Mazak).
- Training and competency assessment for shop-floor operators in total productive maintenance (TPM) programs.
- Field service verification during third-party coolant management audits.
FAQ
Does the PAL-102S require periodic recalibration by an accredited lab?
No—field recalibration is performed daily using distilled water. ATAGO recommends annual verification against NIST-traceable refractive index standards if used in regulated environments.
Can it measure ethylene glycol-based coolants?
No. The PAL-102S calibration curve is specific to typical metalworking fluid chemistries; glycol-based formulations yield non-linear refractive index responses and invalid readings.
What is the minimum sample temperature for reliable measurement?
10 °C. Below this, viscosity increases may cause incomplete prism wetting and air bubble entrapment, leading to erroneous high readings.
Is the prism surface resistant to common cutting fluid additives?
Yes—the sapphire prism resists degradation from amines, biocides, and extreme-pressure (EP) agents commonly found in modern coolant formulations.
How does ATC function without active temperature control?
A calibrated thermistor measures ambient prism temperature and applies a polynomial correction to the raw refractive index reading, referencing all outputs to 20 °C per ISO-defined methodology.
