Ultrasonic flowmeter for liquids

Ultrasonic flowmeters for liquids

ultrasonic flowmeters for liquidsThe Fuji Electric engineers have developed innovative solutions for ultrasonic flow measurement :  PORTAFLOW-C (portable), M-FLOW, TIME DELTA-C (fixed mounted) and the new FST (flange mounted). These instruments are based on transit-time measuring method and are particularly suitable for liquid flow measurement (temperature -40 to +200°C).
Sensors are attached to the outside of the pipeline without cutting or drilling, except for the FST flowmeter.


Measurement principle - Transit time difference method

A pair of sensors are installed on the outside wall of the pipe, facing each other slantingly.  Ultrasonic waves are propagated diagonally between the upstream and downstream sensors.
In one case, the wave is "carried" by the fluid, in the other it is "braked". It therefore takes a different time to switch from one sensor to another. This difference is proportional to the measurement principle of ultrasonic flowmeters for liquid speed and therefore to the flow rate of the fluid.transit time difference method


Anti-bubble measurement (ABM) system

The 32 bits  microprocessor based electronics allows a high accuracy (±1%), a response time of 1 second or less, a very good immunity to air bubbles (ABM system) and to change of fluid pressure and temperature (continuous calculation of sonic speed).

signal averaging




Flange mounted FST flowmeter - High accurate measurement

Three pairs of sensors offer an accuracy of ± 0.2%.  . The FST model is suitable for all energy-saving applications where its high precision and the absence of pressure loss help to reduce consumption and costs.
The FST measurement principle is the transit time difference method with parallel three measuring paths.

Transit time difference method with parallel three measuring paths






  • Water supply and sewage systems  : leakage investigation of water pipe and investigation of the flow direction in the water distribution pipe
  • Thermal or electric power plants : flow rate measurement of the boiler water supply, condenser circulating pump and turbine oil
  • Heating/cooling systems : flow rate measurement of hot water and chilled water in heating and cooling
  • Stations thermales : water extracted quantity measurement
  • Food manufacturing plant : flow rate measurement of raw material and washing water
  • Other industries : flow measurement of all homogeneous liquids capable of ultrasonic wave propagation (service water, sewage, industrial water, seawater, pure water, water for irrigation, oil etc.)


Ultrasonic flowmeters for liquids

Modelsdébitmètre FSTdébitmètre M-flowDébitmètre time Delta-CDébitmètre time delta-C étendu
Mounting methodFlangesClamp-on outside the pipe
Clean liquid with no air bubbles++++++++++
Sewage, drainage+++++
Viscous liquids+++++
Corrosive liquids+++++++++
Non-conductive liquids++++++++++
Low-velocity fluidsna++++
Pulsating fluidsna(1)(1)(1)(1)
High-temperature fluid+++++
High-pressure fluids+++++++++
ProtectionIP66IP65IP66 (IP67 option)IP67IP64
Flange mountedDN50, DN80, DN100 mmnananana
Clamp-on detectorsna FSSA detector
25 to 225 mm (outside diameter) / -40 to +100°c
Capteur FSSA
naFSSC detector
50 to 1200 mm (outside diameter) / -20 to +120°c
Capteur FSSC
naFSSD detector
13 to 300 mm (outside diameter) / -40 to +100°c
Capteur FSSD
naFSSE detector
200 to 6000 mm (outside diameter) / -40 to +80°c
Capteur FSSE
naFSSH detector
50 to 400 mm (outside diameter) / -40 to +200°c
Capteur FSSH
Pressure maxPN40No limit
Fluid temperature-40°C to +150°CDepending on the detector used
Flow velocity0 to ±0.3…10 m/s0 to ±0.3…10 m/s0 to ±0.3…32 m/s
Accuracy±0.2 %±1.5 %±1.0%
Depending on diameter and velocity
Power supply voltage100-240 V AC 50/60 Hz100-240 V AC 50/60 Hz ou 20-30 Vcc100-240 V Ac 50/60 Hz12 hours battery
12 V Ac ou 100-240 V AC

na : Not applicable
(1) : Suitable under conditions
+ : Suitable
++ : Best suitable