Bellingham + Stanley PRH In-line Process Refractometer
| Brand | Bellingham + Stanley (B+S) |
|---|---|
| Origin | United Kingdom |
| Manufacturer Type | Authorized Distributor |
| Origin Category | Imported |
| Model | PRH |
| Pricing | Upon Request |
Overview
The Bellingham + Stanley PRH In-line Process Refractometer is an industrial-grade optical sensor engineered for continuous, real-time measurement of refractive index in flowing liquid streams. Based on the principle of critical angle refractometry, the PRH determines solute concentration—such as sugar, salts, acids, or active pharmaceutical ingredients—by precisely measuring the change in light refraction at the interface between the process fluid and a sapphire prism. Designed for permanent installation directly into pipework, it eliminates manual sampling and offline lab analysis, enabling closed-loop process control and immediate deviation detection. Its robust construction and optical stability make it suitable for demanding environments where hygiene, repeatability, and long-term calibration integrity are essential—particularly in hygienic and regulated manufacturing settings.
Key Features
- High-stability sapphire prism (Mohs hardness 9) resistant to abrasion, corrosion, and thermal shock—ensuring consistent optical performance across extended service life
- Temperature-compensated measurement with selectable compensation algorithms: sucrose-specific (for food/beverage), AG liquid (for organic solvents), or user-defined polynomial correction to 20 °C reference
- Dual-range optical configuration: narrow scale (0–50 °Brix) optimized for high-resolution monitoring in concentrated syrups or pharmaceutical solutions; wide scale (0–95 °Brix) for broad-spectrum applications including molasses or brine
- LED cold-light source operating at 589 nm (sodium D-line equivalent), delivering >100,000 hours of stable luminance without thermal drift or spectral degradation
- Stainless-steel housing (316L grade) and wetted parts compliant with EHEDG and 3-A Sanitary Standards for CIP/SIP compatibility
- Modular electronics architecture supporting analog 4–20 mA output, digital RS-485 Modbus RTU, and optional Ethernet/IP or PROFIBUS DP interfaces for seamless integration into DCS/SCADA systems
Sample Compatibility & Compliance
The PRH supports continuous measurement of clear to mildly turbid aqueous and organic liquid streams—including sucrose solutions, fruit juices, dairy concentrates, ethanol-water mixtures, caustic soda, glycol-based antifreezes, and buffer solutions used in biopharmaceutical downstream processing. It is not intended for opaque suspensions, emulsions, or highly viscous fluids (>500 cP) that may impair optical contact or cause prism fouling. All units are manufactured under ISO 9001:2015 quality management system and bear CE marking. Design and documentation support compliance with FDA 21 CFR Part 11 (when paired with validated data acquisition software), EU GMP Annex 11, and ICH Q7 for pharmaceutical manufacturing. Calibration traceability is maintained via UKAS-accredited reference standards.
Software & Data Management
The PRH operates autonomously but integrates with B+S’ optional ProcessLink™ software suite for configuration, diagnostics, and historical trend analysis. ProcessLink provides audit-trail-enabled logging (meeting ALCOA+ principles), configurable alarm thresholds, batch-level reporting, and export to CSV or OPC UA servers. When deployed in regulated environments, the system supports electronic signatures, role-based access control, and secure firmware updates—facilitating compliance with GLP and GMP documentation requirements. Raw refractive index (nD), temperature, and derived concentration values are timestamped with millisecond precision and stored locally or forwarded to MES/LIMS platforms.
Applications
- Real-time Brix control in juice concentration, jam cooking, and soft drink syrup blending
- Concentration monitoring during evaporation, crystallization, and solvent recovery in fine chemical synthesis
- Batch-to-batch consistency verification in vaccine adjuvant preparation and monoclonal antibody formulation
- In-line sugar content validation pre- and post-pasteurization in dairy processing lines
- Continuous monitoring of cleaning-in-place (CIP) rinse water conductivity equivalence via refractive index correlation
- Quality gate enforcement at filler inlets for ready-to-drink beverages
FAQ
What is the recommended minimum flow velocity for accurate measurement?
A laminar-to-turbulent transition flow of ≥0.3 m/s is advised to ensure uniform prism wetting and eliminate boundary layer effects.
Can the PRH be installed vertically or only horizontally?
It is certified for both orientations; however, vertical installation requires orientation-specific mounting brackets to prevent air entrapment in the flow cell.
Does the instrument require periodic recalibration during operation?
No scheduled recalibration is required under stable process conditions; drift verification using a certified standard solution is recommended every 3–6 months per internal SOP or regulatory protocol.
Is the sapphire prism replaceable in the field?
Yes—the prism assembly is a sealed, user-serviceable module designed for replacement without optical realignment or factory recalibration.
How does the PRH handle temperature fluctuations in ambient plant environments?
The integrated Pt100 RTD measures prism surface temperature with ±0.1 °C accuracy; combined with dual-point thermal modeling, it maintains measurement fidelity across ambient ranges from 0 °C to 60 °C.
