METTLER TOLEDO DHS/L Series In-Line Pipeline Metal Detectors

Overview

The METTLER TOLEDO DHS/L Series In-Line Pipeline Metal Detectors are engineered for continuous, non-invasive detection of ferrous, non-ferrous, and stainless steel contaminants in pumped food products—including liquids, sauces, dairy emulsions, meat slurries, and viscous fillings. Operating on high-frequency electromagnetic induction principles, these detectors generate a stable, uniform magnetic field across the product stream within a sanitary pipeline section. When metallic foreign bodies disrupt this field, the system detects minute impedance shifts with high signal-to-noise ratio—enabling reliable identification down to sub-millimeter particle sizes under dynamic flow conditions. Designed specifically for hygienic process environments, the DHS/L platform integrates directly into existing or new production lines without requiring product diversion, bypass loops, or gravity-fed drop zones—ensuring zero throughput loss and full compliance with modern food safety management systems.

Key Features

• Sanitary in-line architecture with fully drainable, crevice-free 316L stainless steel wetted surfaces conforming to EHEDG and 3-A Sanitary Standards.
• ZMFZ (Zero-Minimum Flow Zone) detection head design minimizes required straight-pipe length upstream/downstream—reducing installation footprint by up to 40% versus conventional inductive detectors and mitigating air entrainment or foaming in low-viscosity products.
• IP69K-rated enclosure (HDS model) certified for repeated high-pressure, high-temperature CIP/SIP cycles; IP65 rating (L Series) suitable for washdown zones with controlled exposure.
• Real-time sensitivity auto-compensation for temperature drift, conductivity fluctuations, and flow-rate variations—maintaining consistent detection thresholds across batch transitions and seasonal ambient changes.
• Modular mechanical interface options: tri-clamp (DIN 11851), SMS 1145, or custom flange configurations; supports integration with volumetric fillers, stuffing machines (e.g., Handtmann twist-fill systems), and pneumatic conveying lines.

Sample Compatibility & Compliance

The DHS/L Series accommodates conductive and non-conductive media with conductivity ranges from 50 µS/cm (dairy whey) to >20 mS/cm (brined meats), and viscosity profiles spanning 1–10,000 cP. Detection performance is validated per ISO 22000:2018 Annex A.3.7 and aligned with FDA Guidance for Industry: Hazard Analysis and Critical Control Point (HACCP) Principles. All units ship pre-configured for compliance with EU Regulation (EC) No. 852/2004 on hygiene of foodstuffs and support full traceability under BRCGS Issue 9 Section 4.10.1 (Metal Detection). The Profile/Signature software enables configurable alarm logging, event timestamping, and operator-level access control—meeting audit requirements for GLP/GMP environments.

Software & Data Management

Controlled via METTLER TOLEDO’s Profile/Signature software suite, the DHS/L Series provides intuitive graphical configuration, real-time diagnostics, and automated calibration verification. The interface supports multi-language operation (EN/DE/FR/ES/ZH), password-protected parameter locking, and configurable alarm escalation protocols (visual, audible, relay output, SCADA notification). Data export adheres to CSV and XML schemas compatible with MES/ERP platforms (e.g., SAP PM, Rockwell FactoryTalk). Full 21 CFR Part 11 compliance is enabled through encrypted audit trails, electronic signatures, and role-based user permissions—certified for use in regulated pharmaceutical-grade food manufacturing facilities.

Applications

• Continuous monitoring of liquid dairy streams (milk, cream, yogurt base) prior to UHT sterilization or filling.
• In-line detection of metal fragments in comminuted meat slurries during sausage batter preparation and stuffing.
• Verification of stainless-steel mesh integrity in processed cheese emulsions and plant-based analogs.
• Post-homogenization screening of infant formula suspensions and nutritional beverages.
• Integration with automated reject systems (pneumatic divert valves, servo-actuated gates) for immediate contamination isolation without line stoppage.

FAQ

What types of metal contaminants can the DHS/L Series reliably detect?

Ferrous (Fe), non-ferrous (Cu, Al, Pb), and austenitic stainless steel (e.g., 304, 316) particles—detection limits vary by product matrix, but typical thresholds range from Ø0.3 mm (ferrous) to Ø1.2 mm (316 SS) in water-based media at nominal flow rates.
Is validation support available for HACCP or BRCGS certification?

Yes—METTLER TOLEDO provides documented IQ/OQ protocols, sensitivity test kits (ASTM F2503-compliant test pieces), and on-site validation assistance aligned with Codex Alimentarius CAC/RCP 1-1969 Annex.
Can the detector operate under full CIP conditions?

The HDS model is rated IP69K and qualified for direct exposure to 80°C, 100 bar water jets; the L Series requires external housing protection during aggressive CIP cycles.
Does the system support integration with legacy PLCs?

Standard communication includes PROFIBUS DP-V1, Modbus TCP, and EtherNet/IP; optional gateways enable compatibility with Siemens S7, Allen-Bradley ControlLogix, and Mitsubishi Q-series controllers.
How often does the system require recalibration?

Factory-calibrated units maintain stability for ≥12 months under stable operating conditions; annual verification using certified reference standards is recommended per ISO/IEC 17025 guidelines.