ATAGO PRM-TANKα Online Refractometer for Tank-Mounted Process Concentration Monitoring

Overview

The ATAGO PRM-TANKα is a high-precision, tank-mounted online refractometer engineered for continuous, real-time measurement of liquid concentration in industrial process environments. Based on the fundamental optical principle of critical-angle refractometry, the instrument determines refractive index (n_D) by measuring the angle at which light transitions between the process fluid and a synthetic sapphire prism interface. This physical property correlates directly with solute concentration—enabling accurate, non-invasive quantification of Brix (% w/w), process-specific concentration (%), and temperature—all compensated automatically across 5–100°C via integrated ATC (Automatic Temperature Compensation). Designed specifically for integration into tanks, reactors, fermenters, extractors, and condensers, the PRM-TANKα eliminates manual sampling and offline analysis, supporting closed-loop process control in food & beverage, pharmaceutical, chemical, and bio-processing industries where consistency, traceability, and regulatory compliance are mission-critical.

Key Features

• Tank-integrated mounting design enables direct weld-in or flange-mounted installation on stainless steel vessels without process interruption.
• Synthetic sapphire prism (Mohs hardness 9) ensures exceptional abrasion resistance and long-term optical stability in aggressive or particulate-laden fluids.
• SUS316L prism housing provides corrosion resistance compatible with CIP/SIP protocols and meets hygienic process requirements.
• High-resolution measurement capability: configurable n_D resolution down to ±0.00001 and Brix resolution down to ±0.01%, supporting both routine QC and R&D-grade applications.
• Robust mechanical architecture rated for 0.98 MPa operating pressure—validated for use in pressurized fermentation tanks and high-flow extraction systems.
• IP67-rated sensor head withstands washdown environments, humidity, and ambient dust exposure typical in production floors.
• Modular architecture separates the wetted sensor head from the remote display/control unit—allowing flexible placement up to 200 meters apart via shielded cabling.

Sample Compatibility & Compliance

The PRM-TANKα is validated for aqueous solutions where refractive index exhibits a stable, monotonic relationship with concentration—including sucrose, glucose, ethanol–water mixtures, organic acids, glycols, and alkaline cleaning agents. It is not intended for opaque, highly viscous (>500 mPa·s), or suspended-solid–rich streams unless pre-filtered. The instrument complies with IEC 60529 (IP67), EN 61000-6-2/6-4 (EMC immunity/emission), and RoHS directives. While not intrinsically safe, it may be deployed in Zone 2 hazardous areas when installed with appropriate barrier systems. Data integrity aligns with GLP/GMP expectations: all measurements include embedded timestamps, temperature metadata, and sensor status flags—facilitating audit-ready records when paired with compliant SCADA or MES platforms.

Software & Data Management

The PRM-TANKα operates as a stand-alone analog/digital transmitter. Its native outputs—4–20 mA (linearized to Brix or n_D) and RS-232C serial data—interface seamlessly with PLCs, DCS systems, or custom HMI software. Optional ATAGO-supplied configuration utilities enable calibration verification, slope/offset adjustment, and unit selection (Brix, % w/w, n_D, °C) via ASCII command protocol. Though the device itself does not store historical data, its real-time streaming output supports integration into FDA 21 CFR Part 11–compliant systems when combined with validated data acquisition hardware and electronic signature workflows. Audit trails, user access logs, and change management can be implemented at the supervisory system level.

Applications

• Fermentation monitoring: Real-time tracking of sugar depletion and alcohol formation in beer, wine, and bioethanol production.
• Extraction process control: Optimization of solvent-to-feed ratios in herbal, botanical, or nutraceutical extractions.
• CIP concentration verification: Ensuring correct caustic or acid dosing during automated cleaning cycles.
• Evaporation endpoint detection: Precise termination of juice or dairy concentrate evaporation based on target Brix.
• Distillation feed control: Maintaining consistent feedstock concentration entering fractionation columns.
• Pharmaceutical buffer preparation: Verification of saline, dextrose, or polymer solution concentrations prior to sterile filtration.

FAQ

Does the PRM-TANKα require periodic recalibration?
Yes—calibration verification against NIST-traceable sucrose standards is recommended before each production shift or at least every 24 hours in high-precision applications. Factory calibration is performed using certified reference materials; field adjustments follow a two-point procedure (e.g., water and 20% Brix standard).

Can it measure non-sugar solutions like NaCl or KOH?
Yes, provided a validated correlation curve between n_D and concentration is established for the specific solute–solvent system. ATAGO provides application support for generating custom calibration tables.

Is the sensor compatible with sanitary tri-clamp fittings?
The PRM-TANKα is supplied with a threaded or flanged process connection; sanitary adapters (e.g., SMS, DIN 11851, or ASME BPE-compliant) are available as optional accessories.

What maintenance is required for long-term reliability?
Routine inspection of the sapphire surface for fouling or scratches; cleaning with soft lint-free cloth and deionized water or approved CIP-compatible solvents. No consumables or moving parts are present.