The KROHNE OPTIFLUX 6400 is the industry standard for hygienic flow measurement in environments where sanitation is non-negotiable. Whether you are batching soft drinks, dosing fruit concentrates, or monitoring milk collection, the OPTIFLUX 6400 delivers a ±0.2% accuracy. Unlike standard meters, its PFA liner is reinforced with a stainless-steel grid, making it fully vacuum resistant during high-temperature SIP (Sterilization-In-Place) and CIP (Cleaning-In-Place) cycles.
Process disturbances like gas bubbles in carbonated drinks or fruit pieces in yogurt often cause signal instability in conventional EMFs. The OPTIFLUX 6400 features Multi Phase Operation (MPO), a sophisticated signal processing algorithm that maintains stable, repeatable readings even during major disturbances. Furthermore, its wireless flowmeter verification capability via Bluetooth® allows maintenance teams to generate NAMUR NE 107 compliant health reports through the KROHNE OPTICHECK Flow Mobile App without ever opening the device or stopping production.
| Category | Detailed Engineering Specification / Technical Data |
| Measurement Accuracy | ±0.2% of MV ±1 mm/s (Reference conditions) |
| Repeatability | ±0.1% of MV (minimum 1 mm/s) |
| Nominal Diameters | DN2.5 to DN150 (1/10" to 6") |
| Measurement Range | Flow velocity up to 12 m/s / 40 ft/s |
| Turndown Ratio | 1000:1 (Ideal for capturing precise dosing and batching) |
| Liner Material | Reinforced PFA with embedded stainless steel grid (Vacuum-resistant) |
| Electrode Material | Stainless Steel 1.4404 (AISI 316L) as standard; Optional: Hastelloy® C, Tantalum, Platinum |
| Gasket Design | Unique L-shaped gasket (Prevents expansion/leakage in hygienic lines) |
| Grounding Method | Virtual Reference (Internal grounding; no grounding rings needed) |
| Process Temperature | -40°C to +140°C (-40°F to +284°F) |
| Ambient Temperature | -40°C to +60°C (-40°F to +140°F); up to +65°C with fan |
| Maximum Pressure | 40 barg / 580 psig (Standard); varies by process connection |
| Media Conductivity | Liquids with conductivity ≥20 μS/cm (Demi water: ≥20 μS/cm) |
| Inlet / Outlet Run | 5D Upstream / 2D Downstream (Recommended for full accuracy) |
| Protection Class | Compact (C): IP66/67 (NEMA 4/4X/6); Remote (F): IP68 (NEMA 6P) |
| Digital Output | HART® 7, Bluetooth® 5.0, Modbus RS485, Profibus DP/PA |
| Analogue / Discrete | Up to 3 x 4…20 mA outputs; Pulse, Frequency, Status, Limit Switch |
| Diagnostics | Integrated OPTICHECK technology (80+ self-monitoring points) |
| Compliance Status | NAMUR NE 107 (Status Recognition), NE 21, NE 43, NE 53, NE 131 |
| Hygienic Approvals | FDA, 3A, EHEDG, EC 1935/2004, EC 2023/2006 |
| Hazardous Approvals | ATEX, IECEx, NEPSI (Zone 1 / Zone 2) |
When specifying the OPTIFLUX 6400, the choice of Hygienic Connection is critical. For dairy and soft drinks, Tri-Clamp or DIN 11851 threaded ferrules are standard. However, for aseptic pharmaceutical lines, we recommend Aseptic Weld End Fittings (DIN 11850) to eliminate potential leak paths. If your product contains large particulates (e.g., fruit chunks), ensure you select a larger bore size to minimize pressure loss and avoid shear damage to the product.
Piping Logic: To maintain high accuracy, ensure a minimum of 5D upstream and 2D downstream straight pipe runs.
Vertical Installation: For products containing solids or for CIP efficiency, vertical installation with an upward flow is preferred. This ensures the pipe is always full and prevents air from being trapped at the electrodes.
Gasket Integrity: The unique L-shaped gasket design of the OPTIFLUX 6400 prevents gasket expansion into the flow stream, which is vital for maintaining a sterile environment and preventing bacterial growth zones.
The OPTIFLUX 6400 is virtually maintenance-free due to its full-bore design with no moving parts. To support your food safety audits (HACCP), use the Bluetooth® interface to perform weekly Wireless Health Checks. The meter can detect electrode coating or conductivity changes in real-time—a sudden drop in conductivity may indicate a shift from product to rinse water, automating your CIP timing.
Traditional gaskets in hygienic flowmeters can expand or contract during high-temperature SIP (Sterilization-In-Place). This expansion often leads to "dead spaces" where bacteria can grow. The OPTIFLUX 6400 uses a unique L-shaped gasket that remains flush with the pipe wall even under thermal stress, ensuring long-term aseptic integrity and extending the service life of the seal.
In the pharmaceutical and beverage industries, liquids often contain fibers or pulp (e.g., fruit juices or protein suspensions). Standard EMFs struggle with the noise generated by these particles hitting the electrodes. The MPO technology in the 6400 uses high-frequency signal sampling to filter this "particle noise." For even more demanding abrasive slurries in non-hygienic sectors, the [KROHNE OPTIFLUX 5400] with its ceramic tube offers a specialized alternative.
The OPTIFLUX 6400 doesn't just measure flow; it monitors the conductivity of the medium with high response times. This allows you to automate the transition between product, rinse water, and cleaning chemicals (acid/caustic) during CIP cycles, reducing water waste. To build a complete automated dosing or filtration skid, pair this meter with our high-precision [Rosemount 3051S Pressure Transmitter] to ensure real-time pressure compensation and system safety.
Q: Can the OPTIFLUX 6400 handle a full vacuum during cleaning?
A: Yes. The PFA liner is reinforced with an embedded stainless-steel grid, preventing the liner from collapsing or peeling away during high-temperature vacuum phases common in aseptic processing.
Q: Does it require grounding rings for plastic piping?
A: No. The Virtual Reference grounding method allows the converter to internally balance potentials, making it possible to measure accurately in plastic or lined pipes without additional hardware, a technology also utilized in the water-specific [KROHNE WATERFLUX 3400].
Q: How do I verify the meter's health for food safety audits?
A: Use the Bluetooth® interface and the KROHNE OPTICHECK Flow Mobile App. You can generate a full verification report in minutes—satisfying HACCP or quality audit requirements without breaking the sterile line.
