FU-TX 320 Clamp-on Ultrasonic Flowmeter

Taiwan-made clamp-on design allows installation without stopping or cutting pipes. Easy maintenance and disassembly reduce costs. External installation ensures zero pipe damage, no blockages, leaks, or pressure issues.

Pipe Size:	TM1：2"～16" (DN 50 ~ 400)
Velocity range:	± 0.1~6.0 m/s
Applicable Fluid:	Clearwater, oil, or
	chemicals with minimal impurities
Fluid Temp:	Standard Probe: 0~80°C
	Heat-resistant Probe: 0~150°C
Accuracy:	< 2% F.S.
Waterproof:	Standard probe IP61
	Chemical-resistant probe IP68
Power Supply:	24VDC 200mA
	100-240 50/ 60Hz AC transformer
Input/Output:	Analog output 4-20mA
	Modbus RTU RS485 2 wired (compatible with NPN/PNP)
Fluid Temp:	Two sets of external PT100
	-40~180°C with 0.1°C resolution

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Clamp-on Ultrasonic Flow Meter

The clamp-on ultrasonic flow meter uses sensors attached to the pipe, requiring no cutting or flow interruption. It is ideal for situations where downtime is not an option and contamination-free measurement is needed. It prevents leakage and pressure issues while ensuring consistent accuracy across different flow conditions.

Principle and Technology

The FU-TX320 ultrasonic flow meter with EchoSense technology calculates flow rate using the formula: Flow Rate = Pipe Area × Flow Velocity. It measures the time difference between faster downstream (A to B) and slower upstream (B to A) signals to determine flow velocity and, consequently, the flow rate.
Learn more: How to Calculate Flowrate

Split Design for Remote Monitoring

The FU-TX series features a split design: the sensors clamp directly onto the pipe, while the display unit mounts on a convenient wall or control cabinet, up to 10 m away via the probe cable. Ideal for elevated or hard-to-reach pipes in mechanical rooms, rooftop cooling towers and ceiling voids, so maintenance staff can read data without climbing. Typical applications include HVAC and chilled water systems, cooling water loops, utility pipelines and oil and gas pipelines.
For smaller pipes : FU-ES Ultrasonic Flow Meter

Patented Metal Clamp

Accurate readings depend on precise probe alignment, especially in opposite-side installation, where the two clamps sit on opposite sides of the pipe with no line of sight between them. LORRIC's patented guide-rail clamp sets the probe position by design, so probes stay in place even under pipe insulation. The same clamp supports same-side and opposite-side installation and resists loosening from gravity.

Simplified Configuration with Built-in Database

Select your pipe and liquid from the built-in database — PVC, PP, PVDF, PFA, stainless steel and copper across CNS/JIS/ASTM/DIN — and FU-TX320 fills in diameter, wall thickness and sound velocity for you. It then calculates the required probe spacing and displays it on screen, ready to guide installation.

Save Time & Cost Without Coupling Gel

Traditional clamp-on flow meters rely on coupling gel to transmit signals through the pipe wall. It's tedious to apply, needs regular replenishment, and is prone to drying, shifting and collecting dirt, all of which degrade accuracy.

On insulated HVAC and chilled water pipes, every reapplication also means removing and re-wrapping the insulation. FU-TX320's TM-1 transducer replaces gel with LORRIC's durable rubber pad, keeping acoustic coupling stable in most installations. The result is a clean, fast install, long-term signal stability, and less maintenance time and fewer consumables. Gel is only needed in special cases, such as thick pipe walls, thick linings or a weak signal.

Multiple Communication Outputs

FU-TX320 supports various communication modes like Analog output with self-powered 16-bit 4-20mA, Modbus RTU RS485. No need for additional communication modules – we've got you covered!
Learn more:
•What is Analog Output
•What is Modbus RTU RS485

Higher Accuracy with Upgraded EchoSense Technology

Improved EchoSense signal processing delivers higher measurement accuracy, better linearity, and reduced zero drift. Built for stable and reliable flow measurement in industrial applications.

Stable Measurement with Anti-Noise Technology

Bubbles, impurities and on-site interference can weaken ultrasonic signals, especially in large HVAC and chilled water pipes. FU-TX320's signal filtering separates the true flow signal from noise such as pump cavitation, variable frequency drive (VFD) electrical noise and mechanical vibration, so readings reflect what is actually flowing in the pipe.

Add Temperature Sensing, Unlock Heat Energy Monitoring

Need heat energy data, not just flow?
Add the optional PT100 temperature sensor pair when you order to enable heat energy (BTU) monitoring on chilled water and cooling water loops. The sensors clamp onto the pipe surface, with no cutting and no extra process connection.

Multiple Connector Options for Easy Installation

Choose IP61 or IP68 TM-1 probes, each with a waterproof connector (standard) or an optional M12 connector for standardized wiring and easier system integration.

DIN Rail Mounting for Wall or Control Cabinet

Whether your meter goes on a plant wall or inside a control cabinet, the DIN rail backplate module covers both. Snap it onto a standard DIN rail to sit neatly with the rest of your panel hardware, or fix the rail to a wall for a stand-alone install.

Flexible Power Supply Options

Choose the power setup that fits your system:

24 VDC external power via 8-pin cable with flying leads (standard)
Optional universal AC to 24 VDC adapter for wider input compatibility

Track Energy Usage to Achieve ESG Goals

The LORRIC FU-TX 320 ultrasonic flow meter features data collection capabilities and can be installed without disrupting equipment operations, helping to prevent business losses. By accurately tracking energy consumption and reducing maintenance costs, it supports effective energy monitoring and reporting, aligning with ESG goals.

Product Specifications

1. Mechanical Specifications
Installation method	Clamp-On
Max. pipe wall working temperature	Standard: 0 ~ 80°C
Max. pipe wall working temperature	High-temp: 0 ~ 150°C
Device working environment temperature	-10 ~ 60°C (14 ~ 140°F)
Applicable pipe size	DN 50 - 400
Power requirement	DC 24V 200mA
Response time	≤ 0.5 ~ 1 second

		DN50	DN65	DN75	DN100	DN125	DN150
Applicable Outer Pipe Diameter	mm	60-63	73-76.3	88.9-90	114.3-117	141.3-144	168.3-171
Applicable Outer Pipe Diameter	inch	2.36-2.48	2.87-3.00	3.50-3.54	4.50-4.61	5.56-5.67	6.63-6.73
Flow Range**	LPM	11.8–707	19.9–1,195	26.5–1,590	47.1–2,827	73.6–4,418	106.0–6,361
Flow Range**	GPM	3.12–186.8	5.26–315.7	7.00–420.0	12.44–746.8	19.44-1,167.1	28.00–1,680.7

		DN200	DN250	DN300	DN350	DN400
Applicable Outer Pipe Diameter	mm	219-222	273-276	324-327	355.6-358	406-409
Applicable Outer Pipe Diameter	inch	8.62-8.74	10.75-10.87	12.76-12.87	14.00-14.09	15.98-16.10
Flow Range**	LPM	188–11,310	295–17,671	424–25,447	577–34,636	754–45,239
Flow Range**	GPM	49.66–2,987.8	77.93–4,668.2	112.01–6,722.4	152.43–9,149.9	199.19–11,950.9

2. Measurement Specifications
Applicable fluid	Liquids with no or small amount of impurities and bubbles
Linearity	± 0.5 % FS (> 0.3 m/s)
Repeatability	± 0.4 %
OR tolerance	10% to 100% of F.S.: ±3.0% OR / 0% to 10% of F.S.: ± 0.3% FS*
Measurement principle	Ultrasonic Time of Flight (ToF)
Measurement range	0.5 ~ 8 m/s
Instantaneous data	Instantaneous flow rate, instantaneous flow velocity
Cumulative data	Cumulative flow (positive, negative or net flow selectable)
Temperature measurement	3-wire PT100
Temperature range	-20 ~ 150°C
Waterproof rating***	Wall-mount host: IP67
Waterproof rating***	Probe: Standard IP61 / IP68 (optional)

* The measurement accuracy of this product is calibrated under controlled laboratory conditions using clean water at room temperature and CNS UPVC pipe fittings. In real-world applications, actual measurement results may differ from laboratory data due to variations in fluid properties, pipe conditions, installation location, and environmental factors.
** Flow range calculated based on 20°C water in PVC pipe.
*** The IP rating (Ingress Protection) classifies the degree of protection an enclosure provides against contact, foreign objects, and water. The format is IPXX: the first digit indicates protection against dust/solid objects, and the second indicates protection against water ingress — higher numbers mean greater protection. For this product: the wall-mount host is rated IP67 (first digit "6" = fully dust-tight; second digit "7" = protected against temporary immersion in water). The standard probe is rated IP61 (second digit "1" = protected against dripping water), with an optional IP68 upgrade (second digit "8" = protected against continuous immersion beyond IP67 conditions).

3. Electrical Specifications
System Power
Power specification	24V 200mA (4-20mA and RS485 currents not included)
Reverse voltage protection	Yes
Optocoupler Output
Power specification	5V ~ 30V 200mA
Reverse voltage protection	Yes
NPN wiring	Supported
PNP wiring	Supported
Max. output frequency	700Hz
Over-current protection	200mA
Analog Current Output (4-20mA, 0-20mA)
Wiring	3-wire
Power	Shared with host power, no separate power needed
Output range	0-20 mA or 4-20 mA (selectable)
Max. output range (incl. error signal range)	0 ~ 21.6 mA (0 ~ 20 mA mode) / 2.4 ~ 21.6 mA (4-20 mA mode)
Resolution	16-bit (0 ~ 24 mA physical range)
Response time	≤ 0.5 ~ 1 second, same update rate as the display
Max Loop resistance	600 ohm @ 24V
Digital Communication Modbus RTU RS485
Baud rate	9600, 19200, 38400, 57600
Wiring	2-wire
Max. nodes per network	256

4. User Interface
Language	English, Traditional Chinese, Simplified Chinese
Unit	Volume: L, ft³, Imp gal, US gal, m³ Time: Minute, Second, Day, Hour Velocity: m/s, ft/s
Display	3-color backlight, 3-line 16-character LCD
Display effective digits	LCD 10 digits (plus sign and decimal point)
Operation buttons	4-key touch buttons
Wired communication	Analog output self-powered 4-20mA / 0-20mA Modbus RTU RS485, 2-wire Optocoupler switch signal (2-meter signal cable included)

Device Size

Unit：mm

Transducer Size

How to Order — FU-TX320

Use the selections below to build your order code. Steps 1–5 configure the main unit; the clamp set is ordered separately with its own part number.

Make a selection for each of the 5 steps. Options marked (Standard) are the default configuration.
Options marked ⚠ Confirm with sales require availability confirmation before ordering.
Select your clamp installation method and pipe size to generate the clamp set code.
Your order codes update live in the “Your order code” section below — copy and include them in your order inquiry.

Temperature sensors must be specified at time of order — they cannot be added after shipment.

Please select your main unit configuration:

1Power supply

— Select power supply —

External 24 VDC supply via 8-pin cable with flying leads (Standard)

Global AC to 24 VDC adapter (universal input)Currently unavailable

2Transducer cableIP rating & connector type

— Select transducer cable —

IP61 TM1 — waterproof connector (Standard)

IP68 TM1 — waterproof connectorAdditional charge

IP61 TM1 — M12 connectorAdditional charge

IP68 TM1 — M12 connectorAdditional charge

3Temperature sensorOptional add-on · enables BTU metering

— Select temperature sensor option —

None (Standard)

10 m PT100 — stainless steel tube type, 1 pairAdditional charge

10 m PT100 — patch type, 1 pairAdditional charge

3 m PT100 — stainless steel tube type, 1 pairCurrently unavailable

3 m PT100 — patch type, 1 pairCurrently unavailable

⚠ Please confirm availability with sales before placing your order. Temperature sensors cannot be retrofitted after shipment.

4Mounting

— Select mounting type —

Screw-mount onto flat surface (Standard), screws not included

DIN rail backplate module, DIN rail not includedAdditional charge

5Communication & power cable

— Select cable option —

2 m, 8-pin cable with flying leads (Standard)

5 m, 8-pin cable with flying leadsAdditional charge

2 m, 8-pin cable + 110 VAC 60 Hz to 24 VDC transformerCurrently unavailable

5 m, 8-pin cable + 110 VAC 60 Hz to 24 VDC transformerCurrently unavailable

Please select your clamp set: (ordered separately with its own part number)

Pipe size:

— Select pipe size —

2"–3" nominal pipe (DN50–DN80)

3"–4" nominal pipe (DN80–DN100)

4"–5" nominal pipe (DN100–DN125)

5"–6" nominal pipe (DN125–DN150)

7"–8" nominal pipe (DN175–DN200)

* Note on clamp availability: The sizes listed reflect current inventory. Once stock is depleted, replacement sizes will be provided: 460 mm clamps → 420 mm, 320 mm clamps → 310 mm, with alternating strap attachment positions.

Your order code

Main unit code: FU-TX320 — — — — — — — — — —

Clamp set code: —

* Options marked Additional charge are subject to additional fees beyond the standard configuration. Please contact LORRIC sales for a quote when making your inquiry.
* Some options shown above are not yet available to order. Please contact LORRIC sales for updates on availability.
* Temperature sensor options are custom add-ons that must be specified at time of order — they cannot be added after shipment. If a factory calibration report is also required, please notify us when ordering as it cannot be arranged afterwards and is subject to an additional charge.
* Pipe sizes refer to nominal pipe diameter (NPS). DN equivalents shown for reference. Contact sales if your pipe OD falls between standard sizes.

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