ATAGO PRM-TANKα Series In-line Refractometer
| Brand | ATAGO |
|---|---|
| Origin | Japan |
| Model | PRM-TANKα Series |
| Measurement Principle | Critical Angle Refractometry |
| Output Signal | 4–20 mA / RS-485 (Modbus RTU) |
| Process Connection | Clamp-type or Flanged (DN25–DN50, sanitary tri-clamp optional) |
| Operating Temperature | −10 to 80 °C (process fluid) |
| IP Rating | IP65 |
| Material | 316L stainless steel wetted parts |
| Accuracy | ±0.05 nD (refractive index), ±0.1 °Brix (typical, sucrose standard) |
| Repeatability | ±0.00002 nD |
| Response Time (T90) | < 2 s |
| Certifications | CE, RoHS, FDA-compliant wetted materials (EPDM/FKM seals available) |
Overview
The ATAGO PRM-TANKα Series In-line Refractometer is an industrial-grade optical sensor engineered for continuous, real-time measurement of refractive index and derived concentration (e.g., °Brix, % w/w, nD) in liquid process streams. Utilizing the critical angle method—where a collimated LED light beam strikes the sapphire prism–liquid interface—the instrument precisely detects the angular threshold at which total internal reflection occurs. This physical optical phenomenon correlates directly with the sample’s refractive index, enabling high-stability, drift-resistant concentration monitoring without consumables or reagents. Designed for permanent installation in pipes, tanks, and mixing vessels, the PRM-TANKα operates under dynamic flow conditions and integrates seamlessly into PLC-controlled manufacturing environments across food & beverage, pharmaceutical, chemical, and bioprocessing industries.
Key Features
- Stainless steel 316L housing with sapphire measuring prism—resistant to abrasion, corrosion, and thermal shock
- Zero-drift optical design with temperature-compensated electronics (built-in Pt100 RTD for automatic compensation from −10 to 80 °C)
- Fast T90 response time (< 2 seconds), supporting closed-loop control of dilution, evaporation, or blending operations
- Dual-output interface: isolated 4–20 mA analog signal (HART-compatible) and digital RS-485 Modbus RTU for SCADA/HMI integration
- Sanitary process connections compliant with ISO 2852 and DIN 11851 standards; tri-clamp (DIN 11851) and flanged variants available
- Configurable linearization tables support custom calibration curves for non-sucrose media (e.g., NaCl, ethanol, organic acids, glycols)
Sample Compatibility & Compliance
The PRM-TANKα accommodates clear to mildly turbid homogeneous liquids—including syrups, juices, brines, cleaning solutions (CIP), fermentation broths, and API intermediates—provided suspended solids remain below 5 µm and do not coat the prism surface. It is unsuitable for emulsions, slurries, or highly viscous fluids (>500 mPa·s) where laminar flow cannot ensure representative sampling at the prism interface. All wetted materials meet FDA 21 CFR §177.2600 requirements for indirect food contact; FKM (Viton®) and EPDM gasket options are certified per USP Class VI. The device conforms to IEC 61326-1 (EMC) and IEC 61000-6-2/6-3, carries CE marking, and supports GLP/GMP data integrity through configurable audit trail logging when paired with ATAGO’s optional PRM-View software.
Software & Data Management
PRM-View PC software (Windows-based) enables full configuration, real-time visualization, trend logging, and report generation (PDF/CSV). It supports multi-sensor networks, alarm thresholds (high/low deviation), and export of timestamped datasets with metadata (sensor ID, calibration date, operator tag). When deployed in regulated environments, the software complies with ALCOA+ principles: data is attributable, legible, contemporaneous, original, accurate, complete, consistent, enduring, and available. Optional firmware upgrades maintain alignment with evolving ISO 8655 (volumetric equipment) and ASTM D1218 (refractive index testing) reference methodologies.
Applications
- Real-time Brix control during juice concentration and evaporation in aseptic processing lines
- Monitoring sugar content in soft drink syrup preparation and carbonated beverage blending
- Tracking NaOH or HNO₃ concentration in CIP rinse cycles to ensure residue-free validation
- Inline verification of ethanol concentration in distillation side-streams or fuel-grade bioethanol production
- Concentration feedback control in crystallization reactors and solvent recovery units
- Batch release testing support for excipient solutions (e.g., dextrose, mannitol) in pharmaceutical manufacturing
FAQ
Does the PRM-TANKα require periodic recalibration?
Yes—ATAGO recommends initial factory calibration traceable to NIST standards, followed by user verification every 3–6 months depending on process severity and regulatory requirements. A two-point calibration (e.g., water + sucrose standard) is supported via PRM-View.
Can it be installed in vertical pipe sections?
Yes, provided flow velocity exceeds 0.3 m/s to prevent air entrapment and ensure consistent prism wetting. Orientation-specific mounting brackets are available upon request.
Is explosion-proof certification available?
The standard PRM-TANKα is not ATEX or IECEx certified; however, intrinsically safe barrier configurations (e.g., using Pepperl+Fuchs KFD2-STC4-Ex1) can be implemented for Zone 2 installations.
How is fouling mitigated during long-term operation?
An optional integrated air-purge fitting (0.1–0.3 MPa clean dry air) is available to periodically clear the prism surface; mechanical wipers are not supported due to optical precision constraints.
What is the warranty and service support structure?
ATAGO provides a 24-month limited warranty covering material and workmanship; extended calibration and preventive maintenance contracts are offered globally through authorized service centers.
