Flow Meters Can Prevent Problems
Flow meters are used to measure the flow of air, fluids and gas. A flow
meter is an instrument used to measure linear, nonlinear, mass or
volumetric flow rate of a liquid or a gas. Many flow meters measure the
volume of the material while other flow meters measure the speed; other
flow meters measure the mass of the materials.
Flow meters are essential for applications that require
precision analysis of the movement of fluids or gases. Some flow meters are
designed to measure for a specific material while other flow meters can detect
a variety of materials. These devices will commonly utilize two different
measuring styles: mass flow or volumetric flow. Devices that calculate for mass
flow determine the characteristic of a material in terms of pounds or kilograms
while systems that measure for volumetric flow will produce results in liters
or cubic inches. Companies that have applications such as brewing, medical
treatments or fuel distribution would benefit from accurate flow meters.
There are several factors that contribute to proper flow meter
operation. For example, if the substance being measured has foreign
contaminants then the flow meter will not register the proper readings. Flow
meters can improve the efficiency of a facility by assisting in monitoring
fluid consumption or other applications. There are several types of flow meter
designs including peak flow meters, water flow meters, fuel flow meters, air
flow meters and ultrasonic flow meters. These instruments can determine the
absolute pressure, differential pressure, viscosity and temperature of the
substance being monitored. There are three typical mounting styles: in-line,
insertion, and non-invasive. Flow meters can also be designed for safety. Flow
meters can transmit data to outside panels to indict pressure or temperature
changes. Vortex flow meters are installed in the flow path of the fluids or
gases and this style meter measures the flow rate by forcing the substances to
move around the sensor. If the readings become alarming then the operator can
act accordingly to avoid a bigger problem.
Most flow meters are made of the primary device, a transducer and a transmitter. These three flow meters parts are usually combined so that the flow meter is one complete instrument. Flow meters vary in terms of measuring technique and design and are therefore used across many fields and industries. Certain flow meters are manufactured using specific materials in order to maximize results. The cleanliness of the air, fluid or gas is an important factor as is the viscosity. The process pressure, process temperature and size of the pipe should also be taken into account. Manufacturers understand how important flow meters are to everyday industrial processes. Flow meters are used for efficiency purposes and to help companies determine profit gain or loss. Industries that benefit from the value of flow meters include the automotive, petroleum, gas, utility services, HVAC, food and beverage processing, chemical and raw material industries.
Some of the most popular flow meters are: peak flow meters, water flow meters, fuel flow meters, air flow meters, ultrasonic flow meters and flow monitor services. Many flow meters measure the volume of the material while other flow meters measure the speed, and still other flow meters measure the mass of the materials. For the most part, flowmeters are used to infer mass flow through calculations that flow meters and flow monitor instruments make after taking various flow measurements, such as absolute pressure, differential pressure, viscosity and temperature. Flow switches, however, typically have a fourth component that serves as a switching unit to control flow. They may also trigger a visual or audible alarm. Flow indicators, which are observation windows in industrial processing lines, aid in measuring flow by visual indicators. Vortex flow meters measure the flow rate by placing an obstruction directly in the flow path, forcing liquids or gases to move around it. When the flow moves around this obstruction, or bluff body, two symmetrical vortices are created on the opposite side, changing the pressure of the flow. A sensor is placed between these vortices to measure these changes in pressure, transmitting this data to an electronic signal conditioner outside the meter.
Flow meter distributors manufacture various instruments for different measurements of flow. Thermal mass flow meters take measurements with two sensors that work together. A temperature sensor reference and an active heated sensor take measurements by calculating how much heat loss occurs in the flowing liquid, and thus these flow meters can determine the flow rate based on this amount. Another type of flow meter is the Coriolis flow meter, which operates on the basis of the Coriolis Effect. In the Coriolis Effect, an excitation force is applied to the flow meter tube, causing the fluid or gas to rotate because the acceleration is acting in opposite directions on both sides of the applied force. A flow meter measurement can then be taken. Other kinds of flow meters operate using sound: these are called ultrasonic flow meters. Another type of flow meter is an electromagnetic flowmeter, which is a type of volumetric flow meter that functions based on Faraday's law of electromagnetic induction. Also, there are rotometers, which utilize a rotating float that moves vertically through a tapered tube. Most of these designs and types are mounted in one of the three basic mounting styles: in-line, insertion and non-invasive.
Flow meter manufacturers offer various instruments for different measurements of flow and there are four main categories of air flow meters that are identified based on how they obtain a reading of the flow rate or quantity of air. Differential pressure air flow meters are the most common type. These devices take both a primary and a secondary measurement and report the difference. The first measurement causes a change in kinetic energy by directing the air through a hole in the flow meter which is measured by the second element. Positive displacement meters separate the air flow into specific volumes which are then counted. Vanes, gears, pistons, or diaphragms are commonly used to divide the air which is counted mechanically or electronically. Velocity air flow meters use a depth measurement and the average air velocity of the flow to produce a reading. They have a greater range than differential pressure devices. The last category is true mass air flow meters. They directly measure the mass of the fluid, not the volume. Each type of flow meter has specific guidelines that must be followed for proper use. For example, when using gas flow meters, the flow meters must remain full of gas. Liquid in gas flow meters can affect the flow meter's accuracy. Similarly, in order for liquid flow meters to work properly, they must remain full of liquid. Gas in liquid flow meters can affect the accuracy of flow meters' readings, as well as contaminants of any kind.
Flow Meters Companies - Sierra Instruments
Flow Meters Companies - Sierra Instruments
Flow Meters Suppliers - GPImeters.com
Flow Meters Suppliers - Hydra-Check
Flow Meters Companies - John C. Ernst Co., Inc.
Flow Meters Suppliers - John C. Ernst Co., Inc.
Flow Meter Types
- are used to measure the flow of air.
are used to measure the force of acceleration resulting from a moving
object towards or away from the center of rotation.
are used to measure the flow of fluids and gases
in a pipe by introducing constriction that causes the pressure to drop.
The pipe must be clean to result in accurate measurements.
- Electromagnetic flow meters measure by creating a magnetic field that is channeled into the liquid
and causes a voltage signal to be sensed that is proportional to the
flow of liquid.
- Flow indicators allow the operator to view the liquid as it is moving. Some models come
equipped with lights to enhance the visibility of the fluids.
measure flow at one position in a pipe, and then, based on the measurement,
they estimate the flow rate for the entire pipe.
- Flow switches are used to monitor fluid or gas flow while it is passing through its valve body, then to send an electrical control sign if the flow rate is too high or too low.
- Flowmeters are used to measure the flow of air, fluids and gases.
- Fuel flow meters are ultrasonic, turbine or positive displacement flow meters
which measure fuel usage rate and remaining fuel quantities in transportation
devices and stationary pumps.
are used to measure gas flow and are one of the more popular flow meters.
This meter is relatively unaffected by changes in temperature or pressure
in the tube or pipe.
are used to measure the flow of liquids when they are open to the atmosphere.
are used by patients with asthma or other lung disorders to measure
the amount of air patients take into their lungs. These flow meters
allow physicians to determine the severity of the illness.
trap liquid to measure its flow by rotating parts
that move between seals and the meter body.
- have a rotating float that moves vertically through a tapered tube.
measure the amount of force that is exerted on a target in a particular
liquid or gas. This should not be used to measure high viscosity liquids
because the target can be damaged.
are meters that use thermal properties of fluids to measure the flow.
The meter is heated and as the liquid flows by, it can tell the flow
rate by the amount of heat lost.
consist of a rotor that measures the fluid when it passes through the
blades. The blade speed is translated into the speed of the fluid
use sound to determine flow rate. Both Doppler Effect meters and time-of-flight
meters are different kinds of this type.
measure by letting the flow stream change the opening
in the meter with a movement of an internal part.
- Vortex flow meters calculate flow rate by measuring the differential pressure of
vortices created downstream from a partial obstruction, or "bluff body"; they
are highly resistant to vibration and are often used in harsh environments.
- are flow meters designed for measuring flow rates of water in various channels, tubes, partially filled pipes, streams, and rivers.
Flow Meter Terms
Absolute Pressure - Atmospheric pressure plus gage pressure in flow
Accumulator - Area where fluid is under pressure and stored as a source
of power within flow meters.
Bluff body - An obstruction, often wedge-shaped, placed in the middle of a
gaseous or liquid flow designed to create a downstream vortex in vortex flow
meters as a means of measuring flow rate.
Control Point - The temperature flowmeter instruments need to maintain to
perform designated functions of flow meters.
Coriolis Force - The force that occurs when a mass has a velocity moving
outward in a rotating plane of flow meters.
Counter Weight - A mass that is added to a particular substance to create
a more balanced and stable apparatus for flow meters.
Current - The flow rate of electricity within flow meters.
Density - A substance's mass per unit of volume in flow meters.
Flow - The travel of materials in response to a force, such as pressure
within flow meters.
Flow Nozzle - A constriction made of a contoured plate that forms a hole
in flow meters for the flow stream so a flowmeter measurement can be taken.
Flow Rate - The velocity of flow in flow meters.
Head-Loss - The loss of pressure in flow meters or a flowmeter system
that is measured with a length parameter (such as amount).
Hot-Tap - Allows for flow meters to be inserted or removed without
causing a complete system shutdown.
Integrator/Totalizer - A flow meters device that measures the total flow
Manometer - Measures fluid pressure. This is a U-shaped flowmeter tube
containing liquid which adjusts with the pressure in the flowmeter tube.
Mass Flow Rate - The volumetric flow rate of a liquid or gas times its
density, expressed as pounds per hour or kilograms per minute in flow meters.
Potential Energy - The potential of energy when a liquid is in a position
or height above a flowmeter place to which it can potentially flow.
Transducer - The part of flow meters that sense fluid as it passes
through the flowmeter device.
Transmitter - The part of flow meters that produce the usable flowmeter
information from the transducer of flow meters.
Weldolet - A connection for a metal pipe that is used to aid as a fitting
for insertion-type sensors or flow meters.