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Smart Clamp on Ultrasonic Flow Meter — LONN-UFM Non-intrusive Liquid Measurement | LONNMETER

The LONN-UFM clamp on ultrasonic flow meter delivers non-intrusive, high-accuracy liquid flow measurement without cutting pipes. Featuring time measurement chip with ≤10ps precision, OLED display with 360° rotation, and magnetic bracket design for easy installation. Supports DN6-DN100 pipes, 4-20mA/RS485 outputs, IP54/IP65 protection. Ideal for chemicals, food, pharmaceuticals, and water treatment.

  • Measurement Principle: Time-of-flight ultrasonic (≤10ps time measurement)
  • Fluid Type: Liquid (water, chemicals, organic solvents, oils)
  • Accuracy: ±2.0% (at 0.3-5.0 m/s)
  • Output Signal: 4-20mA + RS485 Modbus-RTU
  • Protection Class: IP54 / IP65

Product Overview

The LONN-UFM clamp on ultrasonic flow meter represents the next generation of non-intrusive flow measurement technology. Unlike traditional in-line flow meters that require cutting pipes and interrupting processes, the LONN-UFM series clamps directly onto the outside of existing pipes—enabling installation without process downtime, welding, or pipe modifications.

At the heart of the LONN-UFM lies a high-precision time measurement chip capable of detecting time differences as small as 10 picoseconds (10ps). This extraordinary temporal resolution enables accurate flow velocity calculation even at low flow rates, making the clamp on ultrasonic flow meter suitable for both precision dosing applications and high-flow process monitoring.

Why Choose Clamp-On Technology?

Traditional flow meters require cutting into pipes, welding flanges, and disrupting production—costing time, money, and operational continuity. The LONN-UFM clamp on ultrasonic flow meter eliminates these pain points:

  1. No Process Downtime: Install without stopping flow or draining pipes
  2. No Pipe Modification: Clamps onto existing pipes—no cutting, welding, or flange installation
  3. No Moving Parts: Ultrasonic sensors have no mechanical components—maintenance-free operation
  4. No Pressure Drop: External mounting means zero obstruction to flow
  5. Universal Compatibility: Works on steel, stainless steel, copper, PVC, CPVC, PPR, PPH, PFA, HDPE pipes

Time Measurement Chip: The Core Advantage

The LONN-UFM clamp on ultrasonic flow meter integrates an advanced time-to-digital converter (TDC) chip specifically designed for ultrasonic flow measurement. This chip measures the transit time of ultrasonic pulses traveling upstream and downstream along the pipe, calculating flow velocity from the time difference.

Key advantages of the TDC chip:

  • 10ps resolution: Enables accurate measurement even at very low flow velocities
  • High stability: Minimal zero drift over time and temperature variations
  • Fast response: 500ms response time captures rapid flow changes
  • Low power consumption: 24VDC@3W power supply, suitable for solar/battery applications

Technical Specifications

Performance Specifications

Parameter Specification
Accuracy ±2.0% of reading (at 0.3-5.0 m/s)
Linearity ±2.0%
Repeatability 0.8%
Flow Velocity Range 0.1 m/s – 5.0 m/s
Response Time 500 ms
Calibration Factory calibrated on standard water pipe

Pipe Compatibility

Pipe Outer Diameter (OD) DN NPS Flow Range (L/min) Flow Range (m³/h)
9.53 mm DN6 ¼” 0.2 – 20 0.01 – 1
12.7 mm DN8 ⅜” 0.44 – 30 0.03 – 2
15 mm DN10 ½” 0.57 – 50 0.03 – 3
20 mm DN15 ½” 0.92 – 70 0.06 – 4
25 mm DN20 ¾” 1.36 – 150 0.08 – 10
32 mm DN25 1″ 2.71 – 200 0.16 – 15
40 mm DN32 1¼” 4.24 – 330 0.25 – 20
50 mm DN40 1½” 6.8 – 460 0.41 – 30
63 mm DN50 2″ 9.54 – 700 0.57 – 40
75 mm DN65 2½” 14.8 – 1030 0.89 – 60
90 mm DN80 3″ 21.8 – 1360 1.31 – 80
110 mm DN100 4″ 36.5 – 2170 2.19 – 130

Note:

  • Minimum measurable flow: 0.1 m/s
  • Optimal accuracy range: 0.3 m/s – 5.0 m/s
  • Custom sizes available upon request

Pipe Material Compatibility

The LONN-UFM clamp on ultrasonic flow meter works on virtually all common pipe materials:

Metal Pipes:

  • Stainless steel (304, 316, 316L)
  • Carbon steel
  • Copper
  • Ductile iron

Plastic Pipes:

  • PVC / CPVC
  • PPR (Polypropylene Random)
  • PPH (Polypropylene Homopolymer)
  • PFA / PU (Perfluoroalkoxy / Polyurethane)
  • HDPE (High-Density Polyethylene)
  • PVDF (Polyvinylidene Fluoride)

Fluid Compatibility

Suitable Media:

  • Water (tap water, pure water, ultrapure water)
  • Chemicals (dilute sulfuric acid, sodium chlorate, sodium carbonate)
  • Organic liquids (alcohol, ethanol, hydrocarbon)
  • Oils (edible oil, lubricating oil)
  • Solvents (propylene oxide, ethylenediamine)
  • Beverages (wine, juice, soft drinks)

Media Requirements:

  • Single-phase liquid (no bubbles or impurities)
  • Viscosity < 300 CST (mm²/s)
  • Temperature: -10°C to 50°C (compact type)
  • Pressure: stable (no cavitation)

Electrical Specifications

Parameter Specification
Power Supply 24VDC ±10% @ 3W
Analog Output 4-20mA, max load 600Ω
Communication RS485, Modbus RTU protocol
Alarm Output OCT (Open Collector Transistor), up/down limit alarm (optional)
Relay Output 30VDC @ 1A, switching freq < 2Hz (optional)

Display and User Interface

Feature Specification
Display Type 1.54″ 240×240 IPS LCD
Display Rotation 360° (easy reading from any angle)
Display Content Flow rate, velocity, net totalizer, single totalizer, daily max/min, date/time
Display Units m³/h, LPM, GPM, LPH (metric/imperial switchable)
Languages English, Chinese Simplified, Chinese Traditional
Keypad 4 touch keys (menu navigation, value setting)
Data Storage 10 years (64 months, 64 days)
Calendar Battery CR1220

Mechanical Specifications

Parameter Specification
Housing Material Aluminum alloy
Installation Method Clamp-on (upper + lower bracket, 4 screws)
Cable Length Standard 2m (extendable to 20m)
Cable Type Shielded twisted pair
Protection Class IP54 (standard), IP65 (optional)
Environment Temp -10°C to 50°C
Environment Humidity 0-95% RH (non-condensing)
Weight 0.68 – 1.37 kg (model dependent)

Dimensions

Model Pipe OD (mm) A max (mm) B (mm) C (mm)
-9.53 9.53-12.7 97 58 106
-12.7 12.7-14 97 58 106
-15 14-17 97 58 106
-20 17-20 103 58 106
-25 22-30 103 58 106
-32 30-35 108 58 106
-40 38-45 118 68 106
-50 48-54 127 78 106
-63 58-68 143 91 130
-75 68-78 156 105 136
-90 88-96 171 119 150
-110 108-116 194 143 174

Key Features & Benefits

1. Non-Intrusive Installation – Zero Downtime

The LONN-UFM clamp on ultrasonic flow meter clamps onto the outside of pipes without cutting, welding, or process interruption. Installation takes less than 15 minutes:

Installation Steps:

  1. Clean pipe surface (remove paint, rust, dirt)
  2. Attach magnetic bracket (4 screws tighten)
  3. Mount measuring unit (2 screws tighten)
  4. Connect cable and power on
  5. Configure pipe parameters (OD, wall thickness, material)
  6. Perform zero calibration (optional but recommended)
  7. Start measuring

Magnetic Design Advantage: Strong magnets embedded in the bracket prevent screws from falling during installation—especially useful in vertical pipe applications or confined spaces.

2. High-Precision Time Measurement Chip

The core advantage of the LONN-UFM external mounted ultrasonic flow meter is its time measurement chip with 10ps resolution. This enables:

  • Accurate low-flow measurement: Detect flow velocities as low as 0.1 m/s
  • Stable zero point: Minimal drift over time and temperature
  • Fast response: 500ms response time captures flow transients
  • Wide dynamic range: Measure from 0.01 m³/h to 130 m³/h with a single device

3. OLED Display with 360° Rotation

The 1.54″ IPS LCD display can be rotated 360°, ensuring easy reading regardless of installation orientation. Display content includes:

  • Real-time flow rate (m³/h, LPM, GPM, LPH)
  • Flow velocity (m/s)
  • Net totalizer (cumulative flow)
  • Single totalizer (batch flow)
  • Daily maximum/minimum flow
  • Date and time

4. Multi-Language Menu System

The LONN-UFM clamp on flow meter supports three languages:

  • English
  • Chinese Simplified
  • Chinese Traditional

Menu navigation uses a picklist method—simply scroll through options and select. No complex programming or parameter codes to memorize.

5. Data Logging and Storage

The clamp on ultrasonic flow meter stores measurement data for:

  • 10 years (totalizer data)
  • 64 months (monthly totals)
  • 64 days (daily totals)

Data is retained even during power loss (CR1220 battery backup).

6. Flexible Output Options

Standard Outputs:

  • 4-20mA analog output: Proportional to flow rate, max load 600Ω
  • RS485 digital output: Modbus RTU protocol for SCADA/DCS integration

Optional Outputs:

  • OCT alarm output: High/low flow alarm, sensor error alarm
  • Relay output: 30VDC@1A, for pump control or valve interlock

7. Wide Fluid and Pipe Compatibility

Unlike electromagnetic flow meters that require conductive fluids, the LONN-UFM ultrasonic flow meter for pipe works on virtually any liquid:

  • Water (conductive and non-conductive)
  • Chemicals (acid, alkali, organic solvents)
  • Oils and hydrocarbons
  • Beverages and food products

Pipe materials can be metal (steel, copper) or plastic (PVC, PPR, HDPE)—the ultrasonic signal penetrates both.

8. IP54/IP65 Protection

The LONN-UFM external mount flow meter is designed for industrial environments:

  • IP54: Splash-proof, dust-protected (standard)
  • IP65: Waterjet-proof, dust-tight (optional)

Suitable for indoor and outdoor installation (avoid direct sunlight and rain exposure for extended lifespan).

Applications

The LONN-UFM clamp on ultrasonic flow meter is widely used in industries where non-intrusive measurement is essential:

1. Chemical Industry

  • Acid/alkali dosing: Measure flow of dilute sulfuric acid, sodium hydroxide, etc.
  • Solvent blending: Monitor organic solvent flow without contamination risk
  • Batch processing: Use totalizer function for recipe control

Why clamp-on? Chemicals may be corrosive or hazardous—external mounting eliminates leak paths and reduces material compatibility concerns.

2. Food and Beverage

  • Wine production: Measure flow of wine, spirits during fermentation and bottling
  • Juice processing: Monitor flow of fruit juice concentrates
  • CIP (Clean-in-Place) systems: Measure cleaning solution flow without disassembly

Why clamp-on? No crevices or dead legs where bacteria can grow—meets hygienic design principles.

3. Pharmaceutical Industry

  • Purified water systems: Measure ultrapure water flow without contamination
  • Solvent recovery: Monitor organic solvent flow in closed-loop systems
  • Batch recording: Use data logging for batch traceability

Why clamp-on? No intrusion into the process stream—maintains sterility and prevents cross-contamination.

4. Semiconductor Manufacturing

  • Ultrapure water: Measure DI (deionized) water flow in wafer cleaning systems
  • Chemical mechanical polishing (CMP): Monitor slurry flow
  • Wastewater treatment: Measure flow of process wastewater

Why clamp-on? No metal ions leach into ultrapure water—maintains water quality.

5. Water Treatment

  • Intake monitoring: Measure raw water flow into treatment plant
  • Chemical dosing: Monitor coagulant, chlorine, and pH adjuster flow
  • Irrigation: Measure flow to sprinkler systems

Why clamp-on? Easy to install on existing pipes without cutting—reduces installation cost and time.

6. Cleaning Equipment Industry

  • Parts washers: Measure cleaning solution flow in industrial washers
  • Ultrasonic cleaner: Monitor solvent flow in cleaning tanks
  • Spray systems: Measure flow to spray nozzles

Why clamp-on? No obstruction to flow—prevents clogging from particulates in cleaning solutions.

Installation Requirements

Site Selection Guidelines

Proper installation site selection is critical for accurate measurement with the LONN-UFM clamp on ultrasonic flow meter. Follow these guidelines:

1. Full Pipe Condition

Ensure the pipe is always full of liquid. Recommended locations:

  • Vertical pipe with upward flow: Natural full-pipe condition
  • Horizontal pipe: Install at highest point of pipe (top of horizontal run)

Avoid:

  • Pump suction side (may cavitate)
  • Pipe high points where air accumulates

2. Straight Pipe Length

Ultrasonic flow meters require fully developed flow profile. Maintain straight pipe lengths:

Upstream Obstacle Minimum Upstream Length Minimum Downstream Length
Elbow 10D 5D
Tee 10D 5D
Expanded pipe 10D 5D
Reducing pipe 30D 10D
Valve 50D 5D
Pump 50D

Note: D = Pipe outer diameter

3. Pipe Surface Condition

  • Clean pipe surface (remove paint, rust, insulation)
  • No excessive corrosion or scaling inside pipe
  • Uniform pipe wall thickness

4. Temperature Consideration

Ensure pipe surface temperature at measurement point is within transducer limits:

  • Compact type: -10°C to 50°C
  • For higher temperatures, use separate type with high-temp transducer

Installation Steps (Detailed)

Step 1: Clean the Pipe Surface

Use sandpaper or wire brush to remove paint, rust, dirt from the pipe surface at the installation location. A clean surface ensures good ultrasonic coupling.

Step 2: Install the Bracket

  1. Place the lower bracket against the pipe
  2. Align the upper bracket with the lower bracket
  3. Insert 4 M4 screws and tighten evenly
  4. Magnetic design holds brackets in place during installation

Step 3: Install the Measuring Unit

  1. Insert the transducer unit into the upper bracket
  2. Tighten 2 M4 screws to secure the unit
  3. Ensure proper contact between transducer and pipe wall

Step 4: Connect the Cable

  1. Route the cable from the measuring unit to the display host
  2. Connect the cable to the display host socket
  3. Rotate the cable connector to lock it in place

Step 5: Power On and Configure

  1. Connect 24VDC power supply
  2. Power on the display host
  3. Enter setup menu (press key)
  4. Configure pipe parameters:
    • Outer diameter (mm)
    • Wall thickness (mm)
    • Pipe material (steel, stainless steel, PVC, etc.)
    • Fluid type (water, oil, etc.)

Step 6: Zero Calibration (Recommended)

  1. Ensure pipe is full of liquid with no flow (close upstream valve)
  2. Enter setup menu → Calibration → Set Zero
  3. Press “Calibration Zero” 3 times
  4. Wait for calibration to complete (display shows “SQ≥50”)
  5. Open valve to resume normal flow

Ordering Information

When ordering the LONN-UFM clamp on ultrasonic flow meter, please provide the following information:

Required Information

Parameter Options / Specification
Model (Pipe OD) -9.53, -12.7, -15, -20, -25, -32, -40, -50, -63, -75, -90, -110
Pipe Material Stainless steel, carbon steel, copper, PVC, PPR, etc.
Pipe OD (mm) Actual outer diameter of pipe
Wall Thickness (mm) Actual wall thickness of pipe
Fluid Type Water, chemical, oil, etc.
Fluid Temperature (°C) Operating temperature range
Flow Range (m³/h) Minimum and maximum flow rates
Output Signal 4-20mA, RS485 (standard); alarm/relay (optional)
Power Supply 24VDC (standard); 220VAC with converter (optional)
Cable Length (m) Standard 2m; max 20m
IP Grade IP54 (standard); IP65 (optional)

Optional Accessories

  • External power converter: 220VAC to 24VDC (for applications without DC power)
  • Extended cable: Up to 20m (for remote mounting of display unit)
  • High-temperature transducer: For media temperature >50°C
  • Corrosion-resistant transducer: For aggressive chemicals
  • Separate type: Transducer separate from display (for high-temp or hazardous areas)

Example Order

Model: LONN-UFM-50
Pipe Material: Stainless steel 304
Pipe OD: 50 mm
Wall Thickness: 3 mm
Fluid: Water
Fluid Temperature: 20°C
Flow Range: 1-30 m³/h
Output: 4-20mA + RS485 Modbus-RTU
Power Supply: 24VDC
Cable Length: 5m
IP Grade: IP65

FAQ

1. What is a clamp on ultrasonic flow meter and how does it work?

clamp on ultrasonic flow meter is a non-intrusive device that measures flow by clamping onto the outside of a pipe. It works by transmitting ultrasonic pulses through the pipe wall into the flowing liquid. The time difference between pulses traveling upstream and downstream is proportional to flow velocity. The LONN-UFM uses a high-precision time measurement chip (10ps resolution) to calculate this time difference accurately.

2. What are the advantages of clamp-on flow meters over in-line flow meters?

Clamp-on flow meters like the LONN-UFM offer several advantages:

  • No process downtime: Install without cutting pipes or stopping flow
  • No pressure drop: External mounting means zero flow obstruction
  • No contamination risk: No intrusion into the process stream
  • Universal compatibility: Works on any pipe material and most liquids
  • Lower installation cost: No welding, flanging, or pipe modifications

3. What pipe materials and sizes are compatible with the LONN-UFM?

The LONN-UFM external mounted ultrasonic flow meter works on virtually all common pipe materials:

  • Metal: Stainless steel, carbon steel, copper
  • Plastic: PVC, CPVC, PPR, PPH, PFA, HDPE, PVDF

Pipe sizes range from DN6 (OD9.53mm) to DN100 (OD110mm). For larger pipes, contact us for custom solutions.

4. What fluids can the clamp on ultrasonic flow meter measure?

The LONN-UFM can measure most single-phase liquids:

  • Water: Tap water, pure water, ultrapure water
  • Chemicals: Dilute acids, alkalis, organic solvents
  • Oils: Edible oil, lubricating oil, hydrocarbon
  • Beverages: Wine, juice, soft drinks

Requirements:

  • No bubbles or impurities (single-phase liquid)
  • Viscosity < 300 CST
  • Temperature: -10°C to 50°C (compact type)

5. How accurate is the LONN-UFM clamp on flow meter?

The LONN-UFM has an accuracy of ±2.0% of reading at flow velocities between 0.3 m/s and 5.0 m/s. Below 0.3 m/s, accuracy may degrade slightly, but the meter can still measure flows as low as 0.1 m/s.

Accuracy is verified on a calibrated water test loop before leaving the factory. Field accuracy can be optimized by performing zero calibration during initial installation.

6. Can I install the clamp on ultrasonic flow meter myself, or do I need a technician?

The LONN-UFM is designed for self-installation. The magnetic bracket design and touch-key menu system make installation and setup straightforward. No specialized training is required—simply follow the installation guide:

  1. Clean pipe surface
  2. Attach bracket (4 screws)
  3. Mount measuring unit (2 screws)
  4. Connect cable and power on
  5. Configure pipe parameters via menu
  6. (Optional) Perform zero calibration

Total installation time: 15-30 minutes.

For complex applications (hazardous area, high temperature, large pipe), we recommend consulting our technical support team.

Request a Quote

Ready to experience the benefits of non-intrusive flow measurement with the LONN-UFM clamp on ultrasonic flow meter? Contact us today for a customized quote.

When requesting a quote, please provide:

  •  Pipe material and outer diameter (mm)
  •  Wall thickness (mm)
  •  Fluid type and temperature (°C)
  •  Flow range (minimum and maximum m³/h)
  •  Required output signals (4-20mA, RS485, alarm, relay)
  •  Power supply (24VDC or 220VAC)
  •  Cable length requirement (standard 2m or extended)
  •  IP grade requirement (IP54 or IP65)
  •  Any special requirements (high temp, corrosion resistance, etc.)

Contact Information:

Our technical team will respond within 24 hours with a detailed quotation and technical proposal tailored to your application.


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