Wall Mount Ultrasonic Flow Meter | Fixed Pipe & Large Pipe Sensor | FMU833
The FMU833 Standard Wall-Mounted Ultrasonic Flow Meter is a reliable, non-intrusive solution engineered for permanent, long-term liquid flow monitoring. Designed for industrial wall mount installation, the FMU833 utilizes transit-time clamp-on technology to measure clear liquids without cutting pipes or disrupting operation.
Whether monitoring water supply networks, industrial effluent, or large-diameter process cooling loops, the FMU833 delivers consistent performance across pipe sizes from DN15 all the way up to DN6000.
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Key Highlights:
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Fixed wall-mounted design with clear 2-line illuminated LCD display.
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Non-invasive clamp-on sensors (no pressure loss or contamination risk).
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Broad pipe coverage: DN15 to DN6000 (0.5 to 240 inches).
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Industrial output options: 4-20mA, OCT Pulse, Relay, and RS485 Modbus.
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Description
Permanent Ultrasonic Flow Measurement for Industrial Pipelines
The FMU833 is a fixed pipe ultrasonic meter designed for continuous, long-term operational monitoring. Built into a IP67-rated wall-mountable enclosure, this unit processes transit-time ultrasonic signals to compute instantaneous flow rates and cumulative totals for conductive and non-conductive clean liquids.
Because the sensors attach to the outside of the pipe, the FMU833 eliminates system downtime, pressure drop, and potential leakage points associated with traditional inline flowmeters.
Engineered for Large Pipe Flow Sensing
When scaling up to main distribution lines, raw water intakes, or heavy process loops, intrusive inline sensors quickly become cost-prohibitive. The FMU833 serves as a cost-effective large pipe flow sensor capable of handling line sizes up to DN6000. Its digital signal processing automatically adjusts to acoustic variations across different pipe materials—including steel, stainless steel, cast iron, copper, PVC, and fiberglass.
Key Industrial Applications
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Water Treatment & Distribution: Main pipe monitoring, raw water intake, and distribution balancing.
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Industrial Facilities: Cooling water loops, heating water circuits, and process fluid tracking.
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Wastewater & Effluent: Filtered water discharge and effluent monitoring on large pipe runs.
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Facility Infrastructure: Long-term sub-metering where pipe cutting is not permitted.
Features
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Non-Intrusive Clamp-On Design: External transducers eliminate line cutting, system shutdown, and process fluid contact.
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Robust Wall-Mount Enclosure: Designed for fixed control room or field enclosure installation with an easy-to-read 2-line LCD.
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Extreme Pipe Size Versatility: Single main unit supports transducers suitable for pipes from small industrial feeds (DN15) to massive infrastructure mains (DN6000).
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Comprehensive Industrial Communications: Includes standard 4-20mA analog output, OCT pulse, relay outputs, and standard RS485 (Modbus RTU) protocol for seamless integration into PLC and SCADA networks.
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Built-in Data Logging & Totalizer: Features positive, negative, and net flow totalizers alongside non-volatile memory that retains settings and accumulation data during power outages.
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High Temperature & Environment Adaptability: Standard transducers cover typical liquid temperatures (-30°C to 90°C), with optional high-temperature transducers available for continuous thermal loops up to 160°C.
Specification
| Parameter | Technical Specification |
| Model | FMU833 |
| Measurement Principle | Transit-time ultrasonic flow measurement |
| Accuracy | Better than ±1.0% |
| Repeatability | Better than 0.2% |
| Pipe Diameter Range | DN15 mm to DN6000 mm (0.5″ to 240″) |
| Pipe Material | Steel, Stainless Steel, Cast Iron, Copper, PVC, Ductile Iron, FRP, etc. |
| Flow Velocity Range | ±0.03 m/s to ±30 m/s (bi-directional flow) |
| Applicable Liquids | Water, seawater, sewage, oils, chemical fluids, and clean homogeneous liquids |
| Display | 2 x 20 character backlit LCD (instantaneous flow, total flow, signal quality) |
| Signal Outputs |
• 1 x 4-20mA analog output
• 1 x OCT Pulse output
• 1 x Relay output |
| Communication Protocol | RS485 (Modbus RTU) |
| Power Supply | 85–264 VAC or 8–36 VDC |
| Enclosure Rating | Main Unit: IP67 (Wall-mounted) |
| Transducer Temperature Range | Standard: -30°C to 90°C (High-temp option up to 160°C) |
FAQ
Q1: How does the FMU833 differ from compact or portable flow meters?
The FMU833 is engineered specifically for permanent wall-mounted installations where long-term continuous measurement and direct industrial output connections (4-20mA, RS485 Modbus to PLC) are required. It is not a portable battery-powered device or a quick-clip small-tube sensor.
Q2: Do I need to shut down the pipeline during installation?
No. Because the FMU833 utilizes external clamp-on transducers, installation requires no pipe cutting, drilling, or pressure loss. You can install and calibrate the unit while the pipeline is operating normally.
Q3: Can the FMU833 measure flow on very large pipes?
Yes. The FMU833 is specifically suited as a large pipe flow sensor. Depending on the transducer package selected (S2, M2, or L2 transducers), it reliably monitors pipes ranging from small DN15 lines up to massive DN6000 infrastructure pipes.
Q4: What liquid conditions are required for accurate measurement?
The FMU833 performs best on clean liquids or fluids containing negligible amounts of air bubbles or suspended solids (less than 2% by volume), such as potable water, chilled water, light oils, and treated industrial effluent.
