What is electronic flow meter?
How does a magnetic flow meter work?
Magnetic flow meters use a magnetic field to generate and channel liquid flow through a pipe.
A voltage signal is created,
when a conductive liquid flows through the flowmeter’s magnetic field.
The faster the flow of the fluid,
the greater the voltage signal generated.
Electrode sensors located on the flow tube walls pick up the voltage signal,
and send it to the electronic transmitter,
which processes the signal to determine liquid flow.
Let see the video about:
How to Measure Flow with Magnets – (Magnetic Flow Meters)
What is the operating principle of a magnetic flow meter?
The operation of a magnetic flow meter or mag meter is based upon Faraday’s Law,
which states that the voltage induced across any conductor,
as it moves at right angles through a magnetic field,
is proportional to the velocity of that conductor.
E =V x B x D
E = The voltage generated in a conductor
V = The velocity of the conductor
B = The magnetic field strength
D = The length of the conductor
To apply this principle to flow measurement with a magnetic flow meter,
it is necessary first to state that the fluid being measured,
must be electrically conductive for the Faraday principle to apply.
As applied to the design of magnetic flow meters,
Faraday’s Law indicates that signal voltage (E),
is dependent on the average liquid velocity (V) the magnetic field strength (B),
and the length of the conductor (D) (which in this instance is the distance between the electrodes).
In the case of wafer-style magnetic flow meters,
a magnetic field is established throughout the entire cross-section of the flow tube.
If this magnetic field is considered as the measuring element of the magnetic flow meter,
it can be seen that the measuring element is exposed to the hydraulic conditions,
throughout the entire cross-section of the flow meter.
With insertion-style flow meters, the magnetic field radiates outward from the inserted probe.
Magnetic flow meter advantages and disadvantages
Advantages of using Electromagnetic Flow Meters
The main advantages of using mag meters,
is that they require less maintenance,
and can be ordered for very large line sizes.
Some can be installed with a simple hot tap which does not require shutting down the line.
Mag meters also have the benefit of adding a level of trust for consumers:
they hold the service provider accountable for the actual water,
being produced and/or billed.
These efforts will assist with the preservation of our water resources
while improving profitability for the utility.
Disadvantages of using Magnetic Flow Meters
It depends on the meter itself. Some flow tube meters have a liner,
which can separate from the meter causing system damage and requiring maintenance.
Look for a meter that does not require a liner,
such as Sino-Instrument Ultra Mag flanged magnetic meter,
with an NSF-approved, fusion-bonded epoxy liner: the Ultra Liner.
Mag meters don’t work on nonconductive fluids such as oils, steam or gas.
What is a vortex shedding flow meter?
A vortex flow meter is a flow measurement device best suited for flow measurements,
where the introduction of moving parts presents problems.
They are available in industrial grade, brass or all plastic construction.
Sensitivity to variations in the process conditions are low,
and with no moving parts have relatively low wear compared to other types of flow meters.
Vortex flow meters operate under the vortex shedding principle,
where an oscillating vortexes occur,
when a fluid such as water flow past a bluff (as opposed to streamlined) body.
The frequency that the vortexes are shed depend on the size and shape of the body.
It is ideal for applications where low maintenance costs are important.
Industrial size vortex meters are custom built and require appropriate sizing for specific applications.
How does a vortex flow meter work?
The Vortex Shedding flow meter detects the vortices,
that are created by a process medium going past a bluff body.
The frequency of these vortices can be equated into flow velocity,
which, in turn, is used to calculate volumetric flow rate.
The integral temperature sensor is used in saturated steam service,
to determine the operating conditions and specific volume of the steam being measured.
The steam table incorporated into the electronics,
then calculates the flow or energy of the steam flowing through the meter.
The optional pressure sensor can be used for similar calculations,
for gasses and superheated steam.
Intelligent Signal Processing (ISP) provides stable readings, free of external influences.
The Working Principle of Ultrasonic Flow Measurement
Ultrasonic flowmeters use sound waves to determine the velocity of a fluid flowing in a pipe.
At no flow conditions, the frequencies of an ultrasonic wave transmitted into a pipe,
and its reflections from the fluid are the same.
Under flowing conditions, the frequency of the reflected wave is different,
due to the Doppler effect.
When the fluid moves faster, the frequency shift increases linearly.
The transmitter processes signals from the transmitted wave,
and its reflections to determine the flow rate.
How does a fuel flow transducer work?
Fuel flow meters, also known as turbine flow meters, are the main types of speed flow meters. A freely rotatable impeller is installed in the fluid flowing pipe. When the fluid passes, its motion can make the impeller rotate. The larger the fluid flow rate, the larger the kinetic energy and the higher the impeller speed.
The fluid flow can be determined by measuring the number of revolutions or the number of revolutions of the impeller.
Ultrasonic flow meter advantages and disadvantages
Generally, an ultrasonic flow meter is the device,
that uses ultrasound to measure the velocity of liquid flow,
that helps in determining the volume of liquid flow also.
The ultrasonic flow meters are made using the ultrasonic transducers,
which are clamped to the external surface of a pipe,
to generate the ultrasonic pulses through the pipe.
When the liquid flows inside the pipe,
it creates the time difference in the pulses,
and these are examined to calculate the accurate flow velocity of the liquid.
There are many advantages of using the ULTRASONIC flow meters which include:
- The electronics in the ultrasonic flow meter includes ultrasonic flowmeter detector which compensates and adapts to the changes in the profile of the flow, type of the liquid and material of the pipe.
- A portable ultrasonic flow meter converter can be used as a direct method to determine the flow rates effectively when compared to the other flow systems.
- Ultrasonic flow meter converter is inexpensive to use and maintain when compared to the other mechanical flow meters as they are no moving parts in these flow meters.
- Their design is highly sophisticated and they do not obstruct the liquid flow, so they can be used for sanitary, corrosive and abrasive liquids.
These are the advantages of the ultrasonic flow meters and there are many disadvantages of the Ultrasonic flow meter which include:
- The main disadvantage of the ultrasonic flow meter is the cost. The cost of the flow meter is very high when compared to the other types of mechanical flow meters.
- The ultrasonic flow meters are sophisticated when compared to the mechanical flow meters, so it needs experts to repair and maintain the flow meters.
These are the advantages and disadvantages of the ultrasonic flow meters.
Flow Metering Principals
- Differential Pressure Flowmeters
- Velocity Flowmeters
- Positive Displacement Flowmeters
- Mass Flowmeters
- For Open Channel Flowmeters – weirs, flumes, submerged orifices, current meters, acoustic flow meters and more
For different working principle, We offer different types of flow meters, like:
Differential Pressure Flow Meters
The Sonic Nozzle – Critical (Choked) Flow Nozzle
Ultrasonic Doppler Flowmeter
Positive Displacement Flowmeter
Variable Area Flowmeter or Rotameter
Vortex Flow Meter
Open Channel Flowmeters
How to choose your flowmeters?
Important factors when selecting flow metering devices are
- legal constraints
- flow rate range
- head loss
- operating requirements
These factors are more or less related to each other. Example – the cost of flow meters increases with accuracy and lifetime quality.
Which Electronic flow meter do you need? Choose your application below
Magnetic flow meters, also known as mag meters, or electromagnetic flow meters, are widely used in a variety of industrial field applications, due to their reliable flow rate measurements, and features such as low pressure loss and maintenance-free operation.
Waste Water flow meter, also called in-line flow meters, application for water flow rate measurement, in those wastewater treatment industrial pipes. Accurate measurement, control, and reporting are critical in the water and wastewater industry.
Insertion Magnetic Flow Meter, also called insertion electromagnetic flow-meter, is an insertion type flow meter. An insertion flow meter is defined as a meter, that measures flow at a strategic point in a pipe, then uses that measurement to determine the average flow through the pipe.
Vortex shedding flow meter, also called Vortex flow meter. Vortex shedding flow meter is suitable for measuring steam flow rate as well as liquids and gases. Vortex shedding flow meter, easy installation, low cost, analog and 4-20mA output. Pressure & temperature compensation can improve the sensor for more accurate measurement.
Steam Vortex Flow Meters are designed for accurate, cost-effective mass flow measurement of saturated steam. The standard loop powered version of the vortex flow meter, is equipped with the internal temperature compensation required for direct mass flow measurement.
Insertion Vortex Flow Meter measures the volumetric, or mass flow rate of steam, gases, steam in piping conduits, or liquids over a large flow range. The plug-in vortex flowmeter is mainly used for flow measurement of large-diameter gas, liquid and vapor medium fluids in industrial pipelines of various industries.
SI-3128 wall mounted ultrasonic flow meter could be applied to a variety of liquid applications, including ultra-pure liquids, water, chemicals, raw sewage,reclaimed water, cooling water, river water, plant effluent, alcohol, beer, etc.
SI-3000H Portable Ultrasonic Flowmeter is a widely used time difference ultrasonic flowmeter, for on-line calibration and inspection of liquid flow in various industrial sites. With non-contact measurement, high measurement accuracy, large measurement range, battery power, easy operation, easy to carry, built-in data logger and so on.
Handheld ultrasonic flow meter, also known as Portable Doppler flow meter, or Inline ultrasonic flow meter.
SI-2000H handheld ultrasonic flow meter is a representative of portable ultrasonic flow meters.
The SI-2000H handheld ultrasonic flowmeter is small in size and light in weight.
More Electronic Flow Measurement Technology
Compressed Air Flow Meter, is the digital flow meter work for the air compressor. Air consumption is an important info for industrial inline gas flow pipe. According to the measurement conditions, compressed air flow meter could be different types. Thermal mass flow meters, Ultrasonic flow meters, Vortex flow meters, Turbine flow meters. And the differential pressure flow meters (Orifice plate ) are also suitable for compressed air. With the Pressure and Temperature compensation. Sino-Inst’s compressed air flow meters are more affordable and complete.
Gas mass flow meter, are the thermal mass flow meter, which is best choice for gas flow rate measurement. Based on the principle of thermal diffusion, Gas mass flow meter measure the flow rate of gas. Like: air flow, nitrogen, natural gas flow rate. Differential pressure flow transmitter also work for gas flow measurement. With temperature and pressure compem compensation. Gas mass meters calculate mass flow do not require temperature or pressure correction. Thermal mass flow meter can be pipe and insertion type.
Digital Water flow meter, means flow meter that can display water flow rate, and have the output for the flow rate. Like 4-20mA output, HART, RS 485, and so on. Most of Sino-Instrument flow meters are digital water flow meter. Like the electromagnetic flow meter, Portable ultrasonic flow meter, Turbine flow meter…..