Clamp On Ultrasonic Flowmeter Selection Guide: Measure Flow Without Cutting the Pipe
Clamp On Ultrasonic Flowmeter Selection Guide: Measure Flow Without Cutting the Pipe
A plant may already have a working pipeline when someone asks, “Can we add flow measurement here?”
That simple request can become a much bigger job if the selected meter requires the line to be cut, flanges to be added, the process to be stopped, and the pipeline to be modified.
For many existing installations, that disruption is exactly what the maintenance team wants to avoid.
This is where a Clamp On Ultrasonic Flowmeter becomes interesting. The Radical TechArt model shown in the supplied Flow Meter catalogue uses external clamp on sensors and is specifically promoted for installation without cutting the pipe. The brochure lists measurement accuracy of 1% to 2%, pipe coverage from DN25 to DN2000, IP67 protection for the display and IP68 protection for the sensors.
Its biggest practical advantage is therefore not just ultrasonic measurement. It is the ability to add flow monitoring to an existing pipeline with much less mechanical modification.
What Is a Clamp On Ultrasonic Flowmeter?
A clamp on ultrasonic flowmeter measures flow using sensors mounted externally on the pipeline.
The product image on page 3 of the catalogue shows two sensors attached to the outside of a pipe, connected by cable to a separate display unit. Unlike an inline flow meter, the sensors do not need to be installed directly inside the flowing process.
This makes the design particularly useful when cutting an operating pipeline would be inconvenient, expensive, or difficult.
The brochure identifies the measuring principle as Transit Time. In general ultrasonic flow measurement, transit time technology compares the travel time of ultrasonic signals passing with and against the direction of flow. The difference is then used to determine flow velocity.
The brochure itself does not provide the detailed measurement algorithm, so exact calculation methods and configuration requirements should be confirmed from the product manual.
Why Clamp On Installation Matters in an Existing Plant
Consider an operating utility line that was installed years ago without a flow meter.
Adding a conventional inline instrument may involve:
- Stopping the process
- Draining the line
- Cutting the pipeline
- Welding or adding flanges
- Performing leak testing
- Coordinating shutdown work
- Recommissioning the line
With a clamp on ultrasonic system, the sensing arrangement sits outside the pipe.
The catalogue highlights this directly with the statement that installation is easy and there is no need to cut the pipe.
For maintenance and retrofit projects, that can be more important than one additional specification on the datasheet.
It is also useful when a plant wants to add monitoring to a line where permanent mechanical modification is undesirable.
Radical TechArt Clamp On Ultrasonic Flowmeter Specifications
Page 4 of the catalogue provides the main general specifications for the system.
| Parameter | Catalogue Specification |
|---|---|
| Measurement principle | Transit Time |
| Accuracy | ±1% to 2% |
| Display | 2 × 20 LCD backlight display with keypad |
| Output | 4 to 20 mA, Pulse, RS485 |
| Sensor cable | 5 m twisted pair shielded cable |
| Pipe diameter | 25 mm to 2000 mm |
| Process temperature | 30°C to 160°C listed in general specification |
| Ambient temperature | 20°C to 60°C listed in general specification |
| Power supply | 230 V AC or 24 V DC |
| Display dimensions | 132 × 150 × 85 mm |
| Display protection | IP67 |
| Sensor protection | IP68 |
The sensor table on the same page separately shows sensor temperature options of minus 30°C to 90°C and minus 30°C to 160°C. Because these values differ from the general temperature table, confirm the exact temperature range for the selected sensor configuration before placing an order.
Three Clamp On Sensor Sizes
One useful feature of this range is that the same type of flow measurement is offered for very different pipe diameters.
Small Clamp On Sensor
The small sensor covers DN25 to DN100.
Technical points to note:
- Measurement range: DN25 to DN100
- Temperature options shown: minus 30°C to 90°C and minus 30°C to 160°C
- Dimensions: 45 × 25 × 32 mm
Medium Clamp On Sensor
The medium sensor covers DN50 to DN700.
Technical points to note:
- Measurement range: DN50 to DN700
- Temperature options shown: minus 30°C to 90°C and minus 30°C to 160°C
- Dimensions: 64 × 39 × 44 mm
Large Clamp On Sensor
The large sensor covers DN300 to DN2000.
Technical points to note:
- Measurement range: DN300 to DN2000
- Temperature options shown: minus 30°C to 90°C and minus 30°C to 160°C
- Dimensions: 97 × 54 × 53 mm
The three sensor sizes and dimensions are taken directly from the sensor specification table on page 4.
Do Not Select the Sensor by Pipe Diameter Alone
Pipe diameter is the first filter, but it should not be the final selection.
Notice that the sensor ranges overlap.
For example, DN80 falls within the small sensor range of DN25 to DN100 and also within the medium sensor range of DN50 to DN700.
Similarly, DN500 falls within both the medium and large sensor ranges.
That means the pipe diameter alone may not tell you which sensor should finally be ordered.
Before selecting the exact sensor, confirm the application with the supplier, including pipe diameter, pipe material, wall condition, temperature, liquid, and installation arrangement.
4 to 20 mA, Pulse and RS485 Outputs
The catalogue lists three output options: 4 to 20 mA, pulse and RS485.
This makes the flowmeter relevant not only for local indication but also for automation projects.
4 to 20 mA
A 4 to 20 mA signal is useful when the flow value needs to be connected to an analog input on a PLC, controller, recorder, or monitoring system.
Pulse Output
Pulse output can be useful where flow needs to be counted or totalized by a compatible PLC, counter, or flow monitoring system.
The actual pulse characteristics should be confirmed before integration.
RS485
RS485 provides a route for digital communication.
However, one common mistake is assuming that “RS485” automatically means the flowmeter will communicate with any PLC.
Before final selection, confirm:
- Communication protocol
- Baud rate
- Device address settings
- Register information
- PLC or SCADA compatibility
The brochure confirms RS485 as an output, but it does not specify these protocol details.
230 V AC or 24 V DC: Choose According to the Installation
The flowmeter supports 230 V AC or 24 V DC power supply.
This gives the project engineer flexibility.
If the flowmeter is being integrated into an automation panel where 24 V DC instrumentation power is already available, 24 V DC may be convenient.
For other installations, 230 V AC may suit the available site supply.
Do not leave this choice until installation day. Confirm the required supply while placing the order.
IP67 Display and IP68 Sensors
Page 3 lists:
- Display protection class: IP67
- Sensor protection class: IP68
This difference is worth noticing.
The sensors mounted on the pipeline have a higher listed protection class than the display unit. The installation location for the display should therefore be evaluated separately rather than assuming that the entire system carries IP68 protection.
Where Clamp On Ultrasonic Flow Measurement Can Be Useful
The supplied ultrasonic section does not list approved liquids or specific industries, so application suitability should be confirmed before purchase.
In general industrial practice, clamp on ultrasonic measurement is often considered where a plant wants flow information from an existing liquid pipeline without installing a wetted inline sensor.
Typical situations can include:
- Existing utility pipelines
- Cooling and circulation systems
- Water distribution lines
- HVAC and chiller water circuits
- Flow monitoring during plant audits
- Retrofit instrumentation projects
- Large diameter pipelines
- PLC or SCADA flow monitoring projects
These are general use cases for the technology, not a model specific approved application list from the supplied catalogue.
Common Mistakes to Avoid
| Common mistake | Better approach |
|---|---|
| Choosing only by pipe diameter | Confirm sensor size, media, pipe condition and temperature |
| Assuming clamp on means no setup is required | Correct sensor positioning and configuration still matter |
| Ignoring pipe material | Confirm that the selected sensor setup is suitable for the actual pipe |
| Assuming RS485 automatically works with every PLC | Confirm protocol and communication parameters |
| Ignoring temperature limits | Match the selected sensor version to actual pipe temperature |
| Treating the whole system as IP68 | The brochure lists IP67 for display and IP68 for sensor |
| Ordering without confirming power supply | Decide between 230 V AC and 24 V DC beforehand |
| Expecting catalogue accuracy regardless of installation | Proper sensor selection and installation remain important |
Quick Selection Checklist
Before requesting a quotation for a Clamp On Ultrasonic Flowmeter, keep these details ready:
- Pipe outside diameter or nominal DN
- Pipe material
- Pipe wall thickness, if available
- Process liquid
- Normal process temperature
- Required accuracy
- Required output: 4 to 20 mA, pulse or RS485
- Available power supply: 230 V AC or 24 V DC
- Distance between sensors and display
- PLC, SCADA or totalizing requirement
- Indoor or outdoor installation condition
- Required sensor temperature range
Providing this information is much more useful than simply asking for “ultrasonic flowmeter price.”
Specifications to Confirm Before Purchase
The catalogue provides the major product parameters, but the following details are not fully defined in the supplied ultrasonic section and should be confirmed before final selection:
- Approved liquid types
- Pipe material compatibility
- Pipe wall thickness limits
- Required straight pipe length
- Sensor mounting method
- Coupling material requirement
- Actual flow velocity range
- Minimum measurable flow
- RS485 protocol
- Pulse output specification
- 4 to 20 mA scaling
- Totalizer functions
- Displayed engineering units
- Calibration certificate availability
- Exact cable extension options
- Temperature version of the selected sensor
- Hazardous area approval, if required
Why Buy a Clamp On Ultrasonic Flowmeter from Radical TechMart?
A clamp on flowmeter is not a product that should be selected from pipe size and price alone.
The installation has to work with the actual pipe, temperature, signal requirement and control system.
At Radical TechMart, the useful part of the selection process is helping the customer narrow down the correct sensor range, power supply and output configuration before the product reaches site.
That is particularly useful for plant engineers, maintenance teams, OEMs, EPC contractors and system integrators who may need the flow signal connected to a PLC, SCADA system or other monitoring equipment.
Final Thoughts
The biggest reason to consider a Clamp On Ultrasonic Flowmeter is simple: you can add flow measurement without automatically turning the job into a pipeline modification project.
The Radical TechArt range shown in the supplied catalogue covers DN25 to DN2000, uses the Transit Time principle, provides ±1% to 2% stated accuracy, offers 4 to 20 mA, pulse and RS485 outputs, and supports 230 V AC or 24 V DC power. The brochure also offers small, medium and large clamp on sensor options for different pipe diameter ranges.
But the final selection should still be based on the actual pipe, liquid, temperature, sensor range and automation requirement.
A clamp on flowmeter saves you from cutting the pipe. Correct selection saves you from having to solve another problem after installation.
FAQs
1. What is a clamp on ultrasonic flowmeter?
A clamp on ultrasonic flowmeter measures flow using ultrasonic sensors installed on the outside of a pipeline. The Radical TechArt version uses the Transit Time principle and does not require the pipe to be cut for sensor installation.
2. What pipe sizes does the Radical TechArt clamp on flowmeter support?
The catalogue lists an overall pipe diameter range of 25 mm to 2000 mm.
3. What accuracy is specified?
The stated measurement accuracy is ±1% to 2%.
4. Can the ultrasonic flowmeter connect to a PLC?
The brochure lists 4 to 20 mA, pulse and RS485 outputs. These can support control and monitoring integration, but the exact PLC input and RS485 protocol requirements should be confirmed before ordering.
5. What power supply does it require?
The listed options are 230 V AC or 24 V DC.
6. What is the difference between the small, medium and large sensors?
The small sensor covers DN25 to DN100, the medium sensor DN50 to DN700, and the large sensor DN300 to DN2000.
7. Does installation require cutting the pipeline?
The brochure specifically states that installation does not require cutting the pipe.
8. What information should I provide before buying?
Provide pipe size, pipe material, wall thickness if available, liquid, temperature, output requirement, power supply and PLC or monitoring requirements. These details help determine the right configuration.
