Ultrapure liquid flow meters are the ideal solution for measuring fluids that must remain uncontaminated and pure. Used predominantly in the pharmaceutical and power industries, ultrapure liquid flow meters ensure accurate analyses and maintain safety. This type of flow meter ensures that the ultrapure liquid remains free from contamination during the measurement process.nhttp://proteusind.com/flow-meter-for-ultrapure-liquids/n
Ultrasonic flow measurement is based on the principle of transmission and receipt of sound
waves, which have a unique quality of bouncing off most objects - solid, liquid or gaseous. This
technology is vastly different from traditional flow measurement technologies that use turbines
or thermal sensors to measure the flow rate of fluids.
Demand from industry for higher accuracy and lower
costs have led to development of ultrasonic flow
measurement technologies that fulfill meet the
requirements of wide range of applications and
processes. While there are number of different
technologies in ultrasonic measurement currently
available in the market, these can broadly be
categorized into four types. This categorization is based
on the principle on which these technologies are based.
This the original ultrasonic technology developed for
measurement of flow rate of fluids. The technology uses the transit time of sound waves to
measure velocity. An ultrasonic flow meter based on this technology has two ultrasonic
transducers. These transducers act as both transmitters and receivers of ultrasonic sound waves.
To measure the flow rate or velocity of fluid - either gas or liquid through the pipe, the flow
meter alternates between sending and receiving bursts of ultrasonic sound waves through the
transducers. The time taken by the sound waves to travel from the transmitting transducer to the
receiving one gives an exact reading of the velocity of liquid in the pipe.
Ultrasonic Doppler Technology
This technology also works by using two ultrasonic sound
transducers. However, unlike the transit-time technology,
Doppler utilizes one transducer as a continuous transmitter
of ultrasonic sound waves. The other transducer acts as a
continuous receiver. Sound waves introduced into the flow
are reflected or scattered back off suspended particles or
bubbles in the fluid and captured by the receiving
The reflection causes a frequency shift in the sound waves,
which is known as the Doppler Effect. By measuring this
frequency shift it is possible to determine the flow velocity
of the fluid in the pipe. This velocity, when computed with the cross-section area of the pipe
gives the flow rate of pipe flow.
Cross-correlation measurement technology works on the principle that turbulent flow of a fluid is
formed of eddies that have nearly consistent characteristics across a small cross-section of flow.
This is known as the correlation length. A flow meter based on cross-correlation measurement
technology has two ultrasonic sensors placed along the direction of flow of fluid.
The first or upstream sensor picks up the signature of turbulence L/V seconds before the second
or downstream sensor, where L is the distance between the two sensors and V is the velocity of
flow of fluid. The velocity thus turns out to be L/T, where T is the time delay in detection
between the two sensors.
Acoustic Doppler Velocity Profiling Technology
The acoustic Doppler Velocity Profiling technology works on the same principle as the Doppler
technology, with the difference that it uses three transducers instead of two. One of the
transducers is a narrow-beam transducer while the other two are large angle ones. The three
transducers are arranged in a straight line with the narrow angle one positioned directly above
the flow while the other two ones are placed on either side of it.
The middle transducer emits ultrasonic sound waves at a fixed Pulse Repetition Frequency
(PRF), which get scattered from particles within the fluid. The other two transducers receive
these reflected waves and provide a "pulse-to-pulse" algorithm. This in turn allows the
measurement of the Doppler shift in two different directions, which can be used to create a 2D
Take a look at other relevant information about flow meter products and applications including
ultrasonic flow meter for liquids products as well as best ultrasonic flow meter