RBHFM-EF Fixed type Clamp-on Ultrasonic Flowmeter

RBHFM-EF Fixed type Clamp-on Ultrasonic Flowmeter It is a wall-mount,clamp-on type ultrasonic flow meter which uses the transfer time technology.Designed using FPGA chip and low-voltage broadband pulse transmission. 

The use of flowmeters plays a crucial role in various industries, helping to accurately measure fluid flow rates. Among the most advanced and efficient flow measurement devices is the clamp-on ultrasonic flowmeter. This innovative technology has gained significant popularity due to its non-invasive installation method, accurate measurements, and versatile applications.

A major advantage of the clamp-on ultrasonic flowmeter is its non-intrusive installation process. Unlike traditional flowmeters that require cutting and modifying the pipeline, this type of flowmeter can be easily attached to the outside of the pipe without interrupting the fluid flow. This not only eliminates the need for costly and time-consuming installation procedures but also prevents any potential leakage or disruption in the system. Additionally, the non-invasive nature of the clamp-on ultrasonic flowmeter enables its use in sensitive and high-pressure applications where any intrusion into the pipeline is undesirable.

The operating principle of the clamp-on ultrasonic flowmeter relies on ultrasonic waves to measure the flow rate. Two transducers are clamped onto the outside of the pipe, which then emit ultrasonic signals that travel through the pipe wall and interact with the fluid flow. By precisely measuring the difference in time it takes for the ultrasonic signals to travel both upstream and downstream, the flowmeter is capable of accurately determining the velocity and volume of the fluid. This method ensures high accuracy and repeatability, making the clamp-on ultrasonic flowmeter suitable for a wide range of applications, including liquid and gas measurement.

Another key advantage of the clamp-on ultrasonic flowmeter is its versatility. It can be utilized in pipes of various sizes and materials, ranging from small-diameter pipes to large ones made of metals or plastics. This flexibility makes it ideal for industries such as water management, oil and gas, chemical processing, HVAC (heating, ventilation, and air conditioning), and more. Additionally, the clamp-on ultrasonic flowmeter is capable of measuring both forward and reverse flow, allowing for bi-directional monitoring and control. This feature is particularly useful in applications that require accurate measurement of flow rates in both directions.

The clamp-on ultrasonic flowmeter offers several other notable features, including advanced signal processing algorithms, easy-to-use interface, and the ability to transmit data remotely. These features contribute to its user-friendly nature and enhance its usability across various industries. Moreover, the flowmeter can provide real-time data and generate comprehensive reports, enabling operators to monitor and optimize their processes effectively.

In conclusion, the clamp-on ultrasonic flowmeter is a cutting-edge flow measurement device that offers numerous advantages over traditional flowmeters. With its non-invasive installation method, high accuracy, and versatility, it has become a preferred choice for industries requiring precise flow rate measurements. Whether in water management, oil and gas, chemical processing, or any other industry, the clamp-on ultrasonic flowmeter proves to be an indispensable tool for optimizing fluid flow processes and ensuring efficient operations.





  • Principle
  • Features
  • Specification
  • Model Selection
  • Applicants
  • Download

Transit-time meters use a pair of transducers. Both transducers act as transmitters and receivers of these sound wave signals. Sound waves moving in a fluid carry faster when traveling in the fluid flow direction (downstream) and slower when traveling against the fluid flow (upstream). If there were no fluid flow, the times would be identical. This time difference is measured, and from that, a fluid velocity is calculated. With the area of the pipe and fluid velocity known, the meter calculates a volumetric flow rate. If the fluid density is also known, a mass flow rate can be calculated as well.

Transit-time meters are the more versatile of the two types. They are capable of metering liquids, gases and steam. However, typically a single meter will only work with one of these fluid types. Transit-time liquid meters require that the liquid have minimal amounts of particulate solids or entrained bubbles as they can interfere with the sound wave signal.


RBHFM-EF Fixed type Clamp-on Ultrasonic Flowmeter Features:

The clamp-on ultrasonic flowmeter is a non-intrusive device used to measure the flow of liquids in pipes. It is known for its versatility and ease of installation, making it a popular choice in various industries.

The term "clamp-on" refers to the unique feature of this flowmeter, which allows it to be installed on the outside of a pipe without the need for cutting or interrupting the flow. This non-intrusive nature eliminates the risk of leaks or contamination, making it ideal for applications where maintaining the integrity of the fluid is crucial.

The ultrasonic technology used in this flowmeter enables accurate and reliable flow measurement by utilizing sound waves. Transducers, or sensors, mounted on the outer surface of the pipe emit ultrasonic signals that travel through the fluid. By measuring the time it takes for the signal to travel upstream and downstream, the flow rate can be calculated.

One of the main advantages of the clamp-on ultrasonic flowmeter is its ability to measure flow in pipes of various sizes and materials. It can be used on metal, plastic, or even lined pipes, offering a versatile solution for different industries. Additionally, its installation does not require system shutdown or pipe modification, saving time and costs.

The clamp-on ultrasonic flowmeter also offers high accuracy and repeatability, making it suitable for critical applications. It can provide real-time data readings and can be integrated with other control systems for seamless data transfer and monitoring.

In summary, the clamp-on ultrasonic flowmeter is a non-intrusive, versatile, and accurate device for measuring flow in pipes. Its ability to be installed without cutting or interrupting the flow, along with its compatibility with various pipe materials, makes it a valuable tool in the industry. Whether for water treatment, HVAC, or oil and gas applications, the clamp-on ultrasonic flowmeter proves to be a reliable solution for obtaining precise flow measurements.

  • Wide measuring range, a sensor is for DN25-DN1200(1" TO 48").
  • Transducer: ABS, IP68
  • Both Clamp on type sensors and Insertion type sensors are available.
  • Has a 240*128 back lit LCD with 4 line menu display and also the clear, user-friendly menu selections make flow meter more simple and convenient to use.
  • Daily, monthly and yearly totalized flow.
  • Parallel operation of positive, negativeand net flow totalizes with scale factor (span) and BTU Capacity. While the output of totalize pulse and frequency output are transmitted via relay and open collector.
  • Could add the RTD model and temperature sensor become an energy meter to monitoring the energy use, help to save the energy.
  • Not require cutting or drilling the pipe
  • Not cause pressure loss or leakage
  • Measure a wide range of fluids and pipe sizes
  • Easy to install and maintain

RBHFM-EF Fixed type Clamp-on Ultrasonic Flowmeter Specification:

RBHFM Fixed Clamp-on Ultrasonic Flowmeter
Flowrange ±0.09ft/s~±16ft/s(±0.03m/s~±5m/s)
Accuracy ±1% of measured value
Repeatability 0.2% of measured value
Linearity ±1%

1"to 48"(25mmto1200mm).

Pipe size under1”is an option

Fluid Water
Outputs Analog output: 4~20mA, max.load 750Ω.
Pulse output: 0~10KHz
Communication RS232/RS485 Modbus
Powersupply 10~36VDC/1A
Display 240*128backlit LCD
Temperature Transmitter:-14℉~140℉(-20℃~60℃)
Humidity Upto99%RH,non-condensing
Transmitter PC/ABS, IP65
Transducer ABS, IP68
Encapsulated esign
Double-shielded transducer cable
Standard/maximum cable length:30ft/900ft(9m/274m)
Model Selection

The RBHFM-EF Fix Type Transit time Ultrasonic Flow/Heat Meter Model Selction

The RBHFM-EF Fix Type Transit time Ultrasonic Flow/Heat Meter Model Selction
RBHFM-EF Code Type of Transmitter
Accuracy: 1% Ultrasonic Flow Meter
H Ultrasonic Energy/BTU Meter function( RTD)
  RBH Type of transducers(Pipe range: DN25-1200mm)
C1 Clamp-on, IP68. Operating temperature: -40℉ ~ +176℉(-40℃ ~ +80℃)
C2 Clamp-on, IP68. Operating temperature: -40℉ ~ +266℉(-40℃ ~ +130℃)
P1 Insertion, IP68. Operating temperature: -40℉ ~ +266℉(-40℃ ~ +130℃)
1 OCT, Relay,RS232/485, 4-20mA
2 OCT, Relay,RS232/485, 4-20mA,RTD
  Transducers cable length
5 D series type of cable Standard 5m (16ft).
X XX is the length you need for cables, Maximum lengthen to 276m.
  Temperature sensor-Pt1000
N Without
1 A pair of clamp on PT1000 sensor 9m
N Without
1 With SD card
D 10~36VDC
A 90 to 245 VAC
Remark: Model selection sample:
1. Standard configuration: RBHFM-EF-F-C1-15NND RBHFM series Fixed Ultrasonic Flow Meter , C1 type transducer, -40℃ ~ +80℃, IP68 5m cables. Without tenperature sensor and datalogger

The RBHFM-EF Fix Type Transit time Ultrasonic Flow/Heat Meter Application:

the clamp-on ultrasonic flowmeter presents a wide range of application opportunities. Its non-intrusive nature, high accuracy, and versatility make it a reliable choice for flow measurement needs in industries such as HVAC, water and wastewater, oil and gas, chemical processing, power generation, and more.

  • Water (hot water, chilled water, city water, sea water, waste water, etc.);
  • Sewage with small particle content;
  • Oil (crude oil, lubricating oil, diesel oil, fuel oil, etc.);
  • Chemicals (alcohol, acids, etc.);
  • Plant effluent;
  • Beverage, liquid food;
  • Ultra-pure liquids;
  • Solvents and other liquids 



product search