Enterprises that operate in a variety of industries use in their production devices called flowmeters. Using ultrasound, they are able to take into account the amount of water or other fluids consumed.
The need for a flow meter
This device is needed in order to easily measure the amount of substance consumed over a certain period of time. Most often, those who use pipelines keep records of the amount of fuel, liquid, and gas. It is interesting to note that such devices are used not only in industry, but also in everyday life, for example, you can find out the water flow in a house.
How to choose the right device?
In order to correctly select a liquid flow meter, it is necessary to clearly understand the basic requirements that will be presented to it. Therefore, it is important to know the technological parameters and the entire process of its installation.
Here is a list of key issues that you need to clarify before buying such a device:
1. What is the environment (water, air, gases, etc.)?
2. What do you need to measure (total and / or instantaneous flow rate, speed)?
3. If the liquid is not water, then what is its viscosity?
4. Is there a requirement for a local / local display, or will you need an electronic liquid flow meter that automatically displays a signal on the screen?
5. What is the maximum and minimum speed of the source stream?
6. Is the fluid that is inside chemically compatible with the internal surfaces, namely, the contacting parts?
7. The size of the installed pipe?
8. The maximum and minimum pressure and temperature of the press?
9. Is the liquid that is being measured clean?
Ultrasonic Flow Meters
An ultrasonic liquid flow meter uses waves for its operation, which, during accounting, change the propagation velocity in a mobile medium. In the case of installing an ultrasound source and receiver with a bias, the flow velocity can be judged as the sound wave changes along the entire length.
To measure the local tempo, you can use the Doppler effect, for this you need to arrange the source and receiver in parallel, in this case the signals are transferred to the mixer.
An ultrasonic liquid flow meter fixes its frequency at the receiver and changes it depending on the speed of the entire flow, while the initial frequency remains unchanged. The multiplicity of the signal from the mixer at the output is the difference between the frequencies of the received and the initial movement. From this value, one can also judge the local velocity in matter.
Portable flow meter
There is also a portable liquid flow meter that is ultrasonic. This unit is fully equipped with additional accessories and accessories that allow you to solve many problems of measuring the amount of liquid in almost any environment. It helps to take into account substances with a viscosity of up to 300 cSt in almost completely filled pipes with a diameter of 1.2 to 5 cm. The initial kit may include:
- electronic single-channel computer;
- overhead and stationary converters of various types and systems for their installation;
- accessories for measuring heat flux energy and resistance thermometers;
- ultrasonic sensors for calculating pipe wall thickness;
- thermal printer with accessories included in it;
- Software for IBM PC, which is fully compatible with the computer;
- power supply and all accessories that are included in it.
Electromagnetic flow meter
An electromagnetic liquid flow meter is designed to measure substances that conduct electricity. It consists of a measuring tube having a rigid channel cross section and made of dielectric material. A magnetic circuit is installed on the outer surface, which looks like two inductors. Four electrodes are also mounted - two in the vertical and two in the horizontal plane with respect to the measuring tube itself. Vertical electrodes are necessary to account for the electrical conductivity in the pipeline. A sensor that calculates the magnetic field inside the pipe channel is mounted on its surface. It is located in a steel case, on the rack of which an electronic unit is mounted. All wires are brought into it and then they are soldered on a printed circuit board. An external connection moves to the connectors that are located on this chassis. Metal coils that do not respond to the magnet are attached to coils and electrodes, then they are necessarily grounded. Face sealing is performed using a rubber ring. Thanks to this, it is possible to achieve such a technical result in which high accuracy and stability of operation are realized, as well as reliable operation in a wide range of pressures and temperatures.
Doppler flow meters
Such a liquid flow meter is designed to measure a medium that contains sound reflectors, namely gas bubbles or suspended solids. These devices come in three different forms. The family of meters includes both non-invasive devices and introductory probes for the application, which are used for pipes with insufficient transmission of ultrasound.
Standard features of such devices are:
- designs that have clamps;
- programmable interface;
- 8-digit LCD counter;
- power supply with adjustable characteristics;
- housing with good protection;
- pipe sizes can vary from 0.25 inches to 6mm;
- additional double exits;
- pulse repetition rates and relay output.
Mechanical counter
A mechanical fluid flowmeter is a device in which electronic components are completely absent. They can measure the flow velocity, for example, the speed of a mechanical turbine when immersed in a medium. Very often, such devices are used on dryers, diesel generators, burners and boiler rooms.
A mechanical meter is a flow meter for a viscous fluid, so it is used to account for refined petroleum products. All devices are perfect for measuring fuel, which moves by gravity. The standard device in its kit has a mechanical roller counter, complete with an LCD display or a pulse output are also possible. The meter itself and all places of its connection are sealed in order to avoid the peculiar markups of testimonies that the inhabitants of our country love so much.
Heat flow meters
The thermal fluid flow meter in its work has a rather simple idea: if we locally measure the properties of the substance in the stream, for example, it will be the temperature, and begin to register all changes at a certain place from the impact zone, then we can fix the average speed of movement of any substance. If the medium is stationary, then the temperature begins to rise only due to thermal conductivity, and this process occurs faster, since it is closer to the heating element. With this analysis of the data collected from all sensors, it is possible to determine the speed of movement of the substance in any stream.
Vortex flow meters
A liquid flow meter of this type has in its design a main element, which is a spherical or disk-shaped target mounted on an elastic cable, one part of which is fixedly mounted. The flow of gas or liquid leads to the fact that the target is displaced, which causes the cable to shift, and the strain gauges that are attached to it record the degree and type of deformation. The data that are obtained allows us to judge the speed of motion in a substance, as well as its direction.
The main advantages of such sensors is the ability to carry out all measurements in several directions, in which the used flowmeter works. The liquid meter, in order to provide similar multitasking, has symmetrical targets for all necessary directions.
Coriolis flowmeters
Most often, these flowmeters consist of a tube to which a vibration effect from an external oscillation generator is applied. If it is empty, swaying can lead to synchronous acceleration of all its sections. If the fluid moves through the tube, the Coriolis force will also act on it, which will be directed in different directions for the output and input flow, this will lead to a shift in the periods of oscillation. The magnitude of the phase mismatch depends primarily on the mass of the measured liquids, which occur per unit time.
The main advantage of devices of this type is their universality - they can be used to measure the flow rate of a sufficiently large range of substances. But there is a drawback - this is their high cost, which can be afforded mainly by large enterprises.
Micronics Flowmeters
Reducing the amount of fluid is an important factor that characterizes the energy efficiency of facilities and buildings. This well-known brand has a wide range of portable fluid flow meters that do not require a pipe insert. The Portaflow 330 Series provides accurate and quick measurement of the amount of raw material consumed, and is easy to manage thanks to its intuitive menu and on-the-fly customization options. The measurement procedure itself takes literally a few minutes. The devices are quite compact and reliable, and also differ in their stable performance characteristics for a fairly long-term use in production.
The basis of Micronics flowmeters is the so-called “time-of-flight” technique, with which you can measure the frequency of two-dimensional propagation of ultrasound, which is produced by special sensors mounted on the pipe. The speed of the signal passing through the liquid in the pipe becomes greater in the case of the direction of the signal along the stream, and in the opposite direction the indicators no longer coincide and the speed of the ultrasonic signal decreases.
Siemens flowmeters
This brand represents both stationary and overhead liquid flowmeters. Today, the MAG 5100w sensor is considered the leader. It is a compact instrument with very precise specifications. It is used for instant measurements of clean and waste water. For its operation, a power supply of 220 or 24V, as well as a completely filled pipeline, will be required. If it is empty, the device will show this using a relay. The transmitter is most often mounted on top of the sensor, but you can also use an additional installation kit that contains a cable so that the device can be controlled remotely. It is also important that the devices can be sealed, thereby increasing its protection class to IP68. Thanks to this, it can be used with a sufficiently long dive or flooding.
Key Benefits of Siemens Flow Meters
- High repeatability and accuracy gives full confidence in accounting for all flows.
- The devices have a high-quality and durable design, without parts that move. This means that wear is very slow, so maintenance is not required for a long time.
- There is control over the filling of the pipeline, which will warn about the operation of the device in an empty pipe, thereby reducing the likelihood of erroneous measurements.
- The backlight of the keyboard and display helps the user to easily control all settings and measurements.
- Bidirectional flow metering provides the user with all the information about movement in the pipeline.
- SENSORPROM ™ technology guarantees automatic downloads of metrological indicators of the device.
- The flow convector is installed compactly or remotely using brackets that are attached to the sensor.
Most often used for measuring wastewater or drinking water, as well as for metering liquids for chillers and test benches.
Having examined the two companies that manufacture sensors, we can conclude that each of them deserves to exist in the market, since Micronics and Siemens are engaged in meters for different purposes. Both brands are responsible for their high quality and long service life due to the fact that they have been developing and introducing new technologies in this industry for more than a year.