Among many measurement devices like flowmeters and transmitters, JLC International is proud to be a distributor of ultrasonic flowmeters.
There are two basic types of ultrasonic flowmeters:
- Non-invasive inline
The ultrasonic transducers of clamp-on ultrasonic flowmeters are mounted on the external surface of the pipe and are used to generate pulses, which are passed through the pipe. The flowing liquid causes time differences in the ultrasonic signals, which are then evaluated by the electronics of the flowmeter to produce an accurate flow measurement.
The flowmeter works on the transit time ultrasonic principle. This, put simply, involves sending and receiving ultrasonic pulses from a pair of sensors and examining the time difference in the signal. This is a more direct method of determining flow rates than some other systems, and it provides more reliable measurements.
The key principle of the method applied is that sound waves travelling with the flow will move faster than those travelling against it. The difference in the transit time of these signals is directly proportional to the flow velocity of the liquid and consequently the volumetric flow rate.
While elements such as flow profile or the type of liquid and pipe material could have an effect on the measurement, the electronics of the flowmeter compensate for and adapt to changes in the medium in order to provide reliable measurements.
Another method used with ultrasonic flowmeters is the Doppler Effect, which basically sends a signal from clamp-on transducers to be reflected by particles or gas bubbles in the liquid. A new innovative method is the Refracted Spread Spectrum Analysis; it is a development of the older Doppler measurement system, using the frequency of emitted sound shifts in relation to a non-moving receiver.
The non-invasive inline ultrasonic flow meters are mounted in a pipe section, but because of the use of true-bore flow tubes, without moving parts or other obstacles, it is considered non-invasive. However, the term is somewhat arbitral, since pressure, viscosity, chemical compatibility, and even flow pattern can play a large role in the outcome of the measurement.
For example: the ultrasonic flowmeter, Atrato, is an exceptional new way of measuring flow. The flow tube is straight and true-bore with no obstacles like electrodes and no moving parts. The signal transducers (ceramic crystals) are plain disks with a hole in the center that forms a washer, which allows them to be mounted on the circular flow tube. The crystals are excited in such a way that they oscillate radially as opposed to the normal mode of excitement which is across the thickness of the ceramic. Their measuring principle is transit-time.
To learn more about our ultrasonic flowmeters, don’t hesitate to contact JLC International. As a proud distributor, we strive to provide a selection of ultrasonic flowmeters of the highest quality for all types of applications. Those who have inquiries or interest are asked to please fill out a contact form or call us at: 1-888-358-2518.