Clamp-on ultrasonic flow meter uses the transit time principal to measure the difference between transit times of an ultrasonic signals generated by a pair of transducers that are mounted directly onto the pipe. It is suitable for applications where non-intrusive measurement is required – ideal for large diameter pipeline, retrofit installations where pipe cutting and plant shutdown are not allowed.
Clamp-on ultrasonic flow meter is commonly used for applications like chilled and hot water for HVAC system (heating, ventilation, and air conditioning); energy management system; chemical processing; water and wastewater treatment, food and beverage processing etc.
- Non-intrusive measurement method
- Thermal energy calculation (BTU) (optional) (used with a pair of temperature sensor probes)
- Transducers mounted directly on pipe (insulation must be removed)
- Flexibility in mounting configurations
- Wide range of pipe sizes and pipe materials
- Unaffected by changes in temperature, density or viscosity
- No pressure drop, low cutoff
- Bi-directional flow capability
- Corrosion-resistant, contamination free
- Relative low power consumption
- Datalogging function (optional)
Ultrasonic transducers can be configured to operate in either Reflect, Direct, or Double Reflect modes. The choice of operating mode is dictated by the size, material, and age of the pipe; and determines the appropriate mounting option for the transducers onto the pipe.
Direct Mount (Z method): Provides a shorter sonic path which will improve signal strength in difficult pipe conditions such as older and/or corroded piping. The shorter path also minimizes the distance between transducers and can be the best option if mounting space is limited.
Reflect Mount (V method): The transducers are inline with each other making separation distance and alignment easy.
Double Reflect Mount (W method): Ideal for smaller pipe installations. The longer path ensures the transducers won’t touch and the lengthened transit time reduces measurement error.

HVAC and Building Services
Used for chilled water, condenser water, and hot water circulation systems in heating, ventilation, and air conditioning (HVAC) applications. The flow meter is widely integrated into building energy management systems for monitoring energy consumption and optimizing system efficiency.
Water and Wastewater Treatment Plants
Suitable for measuring raw water, treated water, sludge return lines, cooling water, and process water without interrupting plant operations. The non-invasive installation is beneficial in existing plants where shutdowns are difficult or costly.
Chemical and Process Industry
Used for corrosive, hazardous, or high-purity liquids where direct contact with the fluid should be avoided. Since there are no wetted parts, the risk of contamination and material compatibility issues is minimized.
Food and Beverage Industry
Ideal for hygienic processes involving purified water, beverages, or cleaning systems (CIP), where pipe penetration may introduce contamination risks or require additional sanitary certification.
Temporary Flow Surveys and Troubleshooting
Portable clamp-on ultrasonic flow meters are widely used for system diagnostics, performance verification, pump efficiency testing, and energy audits because they can be installed quickly without modifying the pipeline.
Large Diameter or Existing Pipelines
Particularly suitable for retrofit installations on existing pipelines where installing an inline flow meter would require pipe cutting, welding, or extensive downtime.
- Flow and heat measurement
- Thermal energy calculation (BTU)
- Wide measuring range: DN15 to DN700
- ± 1 to 3% accuracy
- Data logging: 2000 lines of data
- Parameters: Instantaneous flow rate, Velocity, Totalized flow (4 totalizers)
UFMX Ultrasonic Flow Meter >>>
- Flow and heat measurement
- ±1% High accuracy and reliability
- Wide measuring range: DN15 to DN6000
- Totalizer data logging: 512 days/128 months/10 years
- RS485 support wireless network, connect GPRS module to accomplish wireless transmission
- 4 keyboards operation
UFMH Handheld Ultrasonic Flow Meter >>>
- Portable set
- Flow measurement
- Wide measuring range: DN15 to DN700
- ± 1 to 3% accuracy
- Built-in ata logging











