Ultrasonic flow detectors are an important part of ultrasonic flow meters. Ultrasonic flow detectors are also called ultrasonic transducers. Ultrasonic flow detectors measure the volumetric flow of liquid within closed conduits. Ultrasonic flow meters use transit-time differences for measuring flow rates inside pipes from the outside using electronics and digital signal processing technology.

Ultrasonic Flow Detectors

Featured Ultrasonic Flow Meters Clamp-on

Features of Ultrasonic Flow Detectors

  • Built-in magnet, which can be directly attached to the pipe;
  • Can be used in strong electromagnetic interference occasions;
  • After the junction box is filled with glue, the protection level is IP68;
  • Complete specifications, divided into three models: large, medium, and small;
  • Measuring pipe diameter range DN15-DN6000;
  • The temperature range is -30~90°℃; -30~160℃
  • The measurement liquid is relatively wide, including water, seawater, slurry or oil, acid and alkali, and other homogeneous liquids;
  • Non-contact measurement method, lightweight and small size;
  • The installation of the clamp-on ultrasonic flowmeter probe is simple. And different sizes of probes can detect pipes of different pipe diameters. Under the condition of ensuring accuracy, the clamp-on ultrasonic flowmeter can measure the smallest pipe of DN15. The largest can measure DN6000 pipeline;
  • The external clamp ultrasonic flowmeter does not need to destroy the pipeline in the process of measuring the flow rate. The probe can directly touch the straight pipe section. No pressure loss. The flow measurement can be performed on the already installed pipe;
  • Suitable for measuring pipes of different materials. Common ones are metal pipes: stainless steel, carbon steel, cast iron, etc., plastic pipes, etc. There are also pipes with better sound-permeable materials.

Optional Ultrasonic Flow Detectors

Types Picture Spec. Model Measurement Range Temperature Dimension
Clamp on
Small Size TS-2 DN15~DN100 -30~90℃ 45×25×32mm
Medium Size TM-1 DN50~DN700 -30~90℃ 64×39×44mm
Large Size TL-1 DN300~DN6000 -30~90℃ 97×54×53mm
High Temperature Clamp on Small Size TS-2-HT DN15~DN100 -30~160℃ 45×25×32mm
Medium Size TM-1-HT DN50~DN700 -30~160℃ 64×39×44mm
Large Size TL-1-HT DN300~DN6000 -30~160℃ 97×54×53mm
Mounting Bracket Clamp on Small Size HS DN15~DN100 -30~90℃ 318×59×85mm
Medium Size HM DN50~DN300 -30~90℃ 568×59×85mm
Extended EB-1 DN300~DN700 -30~90℃ 188×59×49mm
High Temperature Mounting Bracket Clamp on Small Size HS-HT DN15~DN100 -30~160℃ 318×59×110mm
Medium Size HM-HT DN50~DN300 -30~160℃ 568×59×110mm
Extended EB-1-HT DN300~DN700 -30~160℃ 188×59×49mm
MoeldX3-φ6.35X3-φ9.53 X3-φ12.7X3-φ15X3-φ20X3-φ25

Ultrasonic Flow Detectors Working Principle

Ultrasonic Flow Detectors are also called ultrasonic transducers. In fact, it is a piezoelectric ceramic whose frequency is the same as its resonant frequency. It uses the piezoelectric effect of the material to convert electrical energy into mechanical vibration.

Under normal circumstances, ultrasonic waves are first generated by an ultrasonic generator. It is converted into mechanical vibration by the ultrasonic transducer. The ultrasonic wave can be generated by the ultrasonic wave deriving device and the ultrasonic wave receiving device.

Ultrasonic transducers mainly include shell, acoustic window (matching layer), piezoelectric ceramic disc transducer, backing, lead-out cable, receiver, and other parts.

Among them, the piezoelectric ceramic disc transducer plays the same role as a general transducer. It is mainly used to transmit and receive ultrasonic waves, and above the piezoelectric ceramic disc transducer is the receiver. It is mainly composed of lead cables, transducers, metal rings, and rubber washers. Used as an ultrasonic receiver. Receive the Doppler dial-back signal generated outside the frequency band of the piezoelectric ceramic disc transducer.

Ultrasonic transducers are piezoelectric ceramics that resonate at ultrasonic frequencies. The piezoelectric effect of the material converts electrical signals into mechanical vibrations. The ultrasonic transducer is an energy conversion device. Its function is to convert the input electric power into mechanical power (ultrasound) and then transmit it out. , It consumes a small part of its own power.

Types of ultrasonic transducers: can be divided into piezoelectric transducers, sandwich transducers, cylindrical transducers, inverted horn transducers, and so on.


Transit Time Ultrasonic Flow Meter adopts the measurement principle of the time difference method. It uses the ultrasonic wave emitted by the sensor to propagate in the flowing fluid. The sound wave propagation speed in the downstream direction will increase, and the backward direction will decrease. In the same propagation distance, there will be different transmission times. According to the difference between the transmission time and the measured The relationship between fluid velocity measures the fluid velocity.

The flow rate of the fluid is different in different positions in the tube. The flow rate in the center of the tube is faster than the flow rate near the wall of the tube. The flow velocity distribution of the fluid in the pipeline can be represented by the flow velocity cross-sectional distribution diagram.

By setting the flowmeter and considering the cross-sectional distribution of the flow velocity, the average flow velocity can be calculated. Then the volume flow of the fluid can be obtained according to the cross-sectional area of the pipe.

Clamp on Ultrasonic Flow Meter Working Principle
Extended reading: Ultrasonic flow detectors types

V measure fluid velocity
M ultrasonic reflection times
D pipe diameter
θ The angle between the ultrasonic signal and the fluid
T up The time when the downstream sensor transmits the signal to the upstream
T down Time from upstream sensor to downstream
ΔT = T up – T down

Guess You’ll Like: Ultrasonic flow meters types & technical guide

Doppler ultrasonic flowmeter uses the physical principle of Doppler frequency shift to measuring the water flow velocity. Therefore, the Doppler ultrasonic flowmeter is suitable for measuring fluids containing solid particles or air bubbles. Not suitable for measuring pure water.

The scope of use includes:
Natural rivers, artificial rivers, farmland channels, urban sewers, corporate sewage outlets, sewage treatment plants, etc.

The products comply with the SL/T 186-1997 standard.

It is suitable for environments that require continuous and accurate measurement of flow rate and flow rate. It has obvious advantages such as convenient installation and maintenance, high reliability, and high precision.

Ultrasonic flow detectors are also called ultrasonic transducers. Or it is often understood by people as an ultrasonic flow sensor.

Ultrasonic flowmeter is an application of ultrasonic, which measures the flow of liquid by applying the speed difference method.

  • Can do non-contact measurement;
  • No flow obstruction measurement, no pressure loss;
  • It can measure non-conductive liquids, which is a supplement to the electromagnetic flowmeter for unobstructed measurement;
  • Except for the pipe section type with measurement, there is generally no need for actual flow calibration;
  • In principle, it is not limited by pipe diameter, and its cost is basically independent of pipe diameter.

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Sino-Inst, Manufacturer for Ultrasonic Flow Meters. It can measure a single sound-conducting liquid medium of DN 25—150mm. It can measure even liquids such as water, seawater, oil, and slurry.

Sino-Inst’s Ultrasonic Flow Meter, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, the US, and other countries.