ATAGO CM-800α Online Refractometer for Cleaning Solution Concentration Monitoring

Overview

The ATAGO CM-800α Online Refractometer is an industrial-grade, in-line process analytical instrument engineered for continuous, real-time measurement of refractive index–derived concentration (expressed as Brix % or equivalent mass fraction) in liquid streams. It operates on the fundamental principle of critical-angle refractometry: a collimated light beam passes through a sapphire prism in direct contact with the process fluid; the angle at which total internal reflection occurs is precisely detected by a high-resolution linear CCD sensor and converted into refractive index (nD), which is then correlated to concentration via pre-calibrated polynomial functions. Designed specifically for harsh industrial environments—including CIP (Clean-in-Place) systems, alkaline cleaning loops, rinse tanks, and detergent blending lines—the CM-800α delivers stable, drift-resistant measurements without sample extraction or flow interruption. Its compact, sanitary 316L stainless steel body complies with IP67 ingress protection and supports direct mounting onto DN25–DN50 (1″–2″) process pipes via tri-clamp or flange adapters. Unlike laboratory benchtop refractometers, the CM-800α integrates temperature compensation using a built-in Pt100 RTD sensor (±0.1 °C accuracy), ensuring traceable, repeatable results across operating temperatures from 0 °C to 60 °C.

Key Features

• Real-time, non-invasive concentration monitoring with 1-second response time and ±0.1 Brix repeatability under steady-state flow conditions
• Sapphire measuring prism (Mohs hardness 9) resistant to abrasion, chemical corrosion, and thermal shock—validated for prolonged exposure to NaOH (up to 5 wt%), Na₂CO₃, and low-concentration acidic cleaners
• Integrated temperature-compensated refractive index calculation compliant with ISO 21748 and ASTM D1218 standards for refractometric analysis
• 4–20 mA analog output with HART® protocol support for seamless integration into DCS/PLC systems (e.g., Siemens PCS7, Emerson DeltaV)
• Optional digital interface: RS-485 Modbus RTU for SCADA connectivity and remote configuration via ATAGO’s dedicated configuration software
• Zero-point verification capability using deionized water or air—no calibration solutions required for routine validation

Sample Compatibility & Compliance

The CM-800α is validated for use with aqueous-based cleaning solutions commonly employed in pharmaceutical, food & beverage, and semiconductor manufacturing facilities—including caustic soda (NaOH), sodium metasilicate, sodium carbonate, and low-foaming surfactant blends. It is not suitable for highly viscous fluids (>500 mPa·s), suspensions, emulsions, or solvents with refractive indices outside the instrument’s calibrated range (nD = 1.3300–1.4500). The device meets CE marking requirements per EU Machinery Directive 2006/42/EC and Electromagnetic Compatibility Directive 2014/30/EU. Its wetted parts conform to FDA 21 CFR Part 177.2400 for food-contact polymers and ASME BPE-2022 surface finish specifications (Ra ≤ 0.8 µm). For GMP-regulated environments, optional audit-trail logging and electronic signature support are available via firmware upgrade to comply with Annex 11 and 21 CFR Part 11 data integrity requirements.

Software & Data Management

Configuration and diagnostics are performed using ATAGO’s Windows-based CM-ConfigTool v3.2, which enables user-defined concentration units (Brix, % w/w, g/L), alarm thresholds (high/low deviation), and linearization curve editing. All measurement data—including timestamped nD values, temperature readings, and diagnostic status flags—are timestamped and exportable in CSV format. When integrated with a historian system (e.g., OSIsoft PI, Ignition), the CM-800α supports automated batch reconciliation and SPC charting for cleaning cycle consistency validation. Firmware updates preserve calibration coefficients and configuration settings, ensuring continuity during maintenance cycles.

Applications

• Continuous monitoring of alkaline CIP solution concentration during tank cleaning cycles to ensure minimum effective dosage and reduce chemical overuse
• Feedback control of detergent dilution in centralized cleaning supply systems to maintain target Brix within ±0.2 units
• Verification of rinse water purity post-CIP to confirm removal of residual cleaner (detecting >0.05 Brix carryover)
• Process validation support for FDA/EMA regulatory submissions requiring documented cleaning efficacy
• Integration into PAT (Process Analytical Technology) frameworks for real-time quality assurance in biopharmaceutical manufacturing

FAQ

What concentration range is supported for NaOH solutions?
The CM-800α is factory-calibrated for 0–10 wt% NaOH; custom calibration curves can be generated for up to 15 wt% upon request.
Can it be installed in vertical piping?
Yes—orientation-independent operation is enabled by its symmetrical flow cell design and pressure-rated housing (max. 10 bar at 20 °C).
Is explosion-proof certification available?
ATEX II 2G Ex db IIB T4 Gb / IECEx DBA 22.0022X certification is available as an optional variant (CM-800α-EX) for Zone 1 hazardous areas.
How often does it require recalibration?
Under stable process conditions, annual verification against NIST-traceable sucrose standards is recommended; zero-point checks with DI water should be performed weekly.
Does it support automatic temperature correction for non-aqueous cleaners?
No—temperature compensation algorithms are optimized for aqueous systems; alternative calibration models must be developed empirically for non-aqueous solvents.