For large pipelines (≥DN200 / 8"), traditional inline flowmeters become prohibitively expensive and difficult to install. The KROHNE OPTIPROBE offers a flexible, high-performance alternative. Designed specifically for Non-Revenue Water (NRW) monitoring and District Metering Areas (DMA), this insertion-type electromagnetic flowmeter delivers reliable bi-directional flow data without the heavy infrastructure costs associated with full-bore meters.
The defining feature of the OPTIPROBE is its versatility in existing pipework. Model B features an adjustable insertion length (up to 400 mm) integrated with a ball valve. This allows for hot tapping, meaning the sensor can be installed or removed under full process pressure. This "no-shutdown" capability saves municipalities thousands in avoided downtime and service interruptions during network upgrades.
| Category | Detailed Engineering Specification / Technical Data |
| Measurement Principle | Electromagnetic (Insertion-type) |
| Measured Media | Conductive clean liquids (Water, Wastewater, Effluent) |
| Minimum Conductivity | ≥20 μS/cm |
| Flow Direction | Bi-directional (Forward and Reverse) |
| Applicable Pipe Sizes | ≥DN80 / 3" (Maximum ROI achieved for pipes ≥DN200 / 8") |
| Insertion Lengths | Model A: Fixed length; Model B: Adjustable up to 400 mm / 15.7" |
| Process Pressure | Maximum 16 barg / 230 psig |
| Process Temperature | 0°C to +100°C / +32°F to +212°F |
| Wetted Materials | Non-corrosive materials (Stainless Steel, specialized polymers) |
| Process Connection | Flange EN 1092-1: DN40 (standard for insertion mounting) |
| Protection Class | IP66/67 (Standard); IP68 / NEMA 4X/6P (Optional for flooding/burial) |
| External Coating | Standard Epoxy; Optional: Offshore Coating or Burial Coating |
| Turndown Ratio | Optimized for network management and trend analysis |
| Analogue Output | 3 x 4…20 mA (HART® 7 compliant) |
| Pulse/Freq Output | Active or Passive pulse, frequency, and status outputs |
| Digital Communication | Modbus RTU, HART®, PROFINET, Profibus-PA/DP, FOUNDATION™ Fieldbus |
| Diagnostic Functions | Electrode coating detection, coil integrity, empty pipe, and more |
| Converter Versions | Compact (C): Integrated; Remote (F): Field- or Wall-mounted |
| Hazardous Approvals | ATEX Zone 2 (II 3G IIC); NEPSI (Ex ic nA II B T3 Gc) |
| Marine Approvals | ABS, BV, CCS, DNV, KR, LR, NK, RINA, CRS, IRS, PRS, RS |
Accuracy vs. Budget: Use the OPTIPROBE for indicative measurements, leak detection, and trend analysis in large networks. If your application requires revenue-grade accuracy (custody transfer) or has zero-diameter (0D/0D) straight run constraints, we recommend the [KROHNE WATERFLUX 3400] battery-powered water meter.
Model Selection: Choose Model A for new installations where pipe drainage is possible. Choose Model B for retrofitting active water mains where a shutdown is impossible (Hot Tapping).
Environment: For subsurface water pits prone to flooding, always specify the IP68 Remote Version with a field-mounted converter for safe access.
Hydraulic Profile: Insertion meters are sensitive to flow profiles. Ensure a straight run of at least 10D upstream and 5D downstream from the insertion point to minimize turbulence errors.
Precise Positioning: The sensor head must be positioned at the critical velocity point (typically 1/8 or 1/2 of the pipe diameter). Always use the KROHNE sizing tool to calculate the exact insertion depth for your specific pipe wall thickness.
Orientation: For best results, install the probe at a 45-degree angle from the top of the pipe to prevent air pockets (at the top) or sediment (at the bottom) from affecting the electrodes.
The OPTIPROBE features extensive self-diagnostics. Because of the Model B's ball valve, the sensor can be retracted for cleaning without draining the line—an essential feature when dealing with effluent or water with high mineral content that might coat the electrodes over time.
In active water networks, shutting down a main line to install an inline meter can cost more in labor and lost revenue than the meter itself. The Model B (Hot Tapping version) allows for installation while the pipe is live. Using a specialized drill and the OPTIPROBE’s integrated ball valve, you can insert the sensor without a single drop of water escaping.
For a DN600 (24") trunk main, a full-bore inline meter represents a significant capital investment and logistical challenge. For non-fiscal applications—such as pump performance monitoring or network balancing—the OPTIPROBE offers the same inductive measurement principle at a fraction of the hardware, shipping, and installation cost.
With a staggering list of Marine Approvals (ABS, DNV, LR), the OPTIPROBE is a premier choice for Ballast Water monitoring and shipboard utility lines. Its optional offshore coating ensures that the sensor body survives high-salinity environments that would corrode standard industrial meters within months.
Like all EMFs, the OPTIPROBE requires a stable reference. In plastic (HDPE/PVC) pipes, we recommend installing grounding rings or ensure the pipe is fully filled to utilize the medium as a reference. This is critical for maintaining signal stability in District Metering Areas (DMA).
While the OPTIPROBE is the king of cost-efficiency for large diameters, it is primarily used for indicative monitoring and trend analysis. If your application requires high-precision fiscal billing or custody transfer in smaller lines (up to DN150), we recommend the compact and highly accurate [KROHNE OPTIFLUX 1400].
Q: Can the KROHNE OPTIPROBE be installed without shutting down the water main?
A: Yes. By choosing Model B, the OPTIPROBE can be installed via Hot Tapping. It features an integrated ball valve that allows the sensor to be inserted or retracted under full process pressure (up to 16 barg), eliminating downtime.
Q: How accurate is an insertion flowmeter compared to an inline meter?
A: While highly reliable for trend monitoring and leak detection, insertion meters are generally less accurate than full-bore meters. For high-precision fiscal billing or custody transfer, we recommend the [KROHNE WATERFLUX 3400].
Q: Is the OPTIPROBE suitable for submerged or underground installation?
A: Yes. We provide a specialized IP68 / NEMA 6P rated version designed specifically for burial or permanent flooding in subsurface pits. Optional offshore coatings are also available for high-salinity environments.
Q: What are the straight pipe run requirements for the OPTIPROBE?
A: To ensure a stable hydraulic profile, we recommend a straight run of at least 10D upstream and 5D downstream from the insertion point.
