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. 

  • 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.





  • 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

  • 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
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:

  • 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 



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