Articles
Newsletters
| How Do Flow Meters Work - Flowmeter Types And Principles |
 |
 |
 |
| Written by Adrian Fletcher |
| Friday, 25 July 2008 07:24 |
|
Flow meters are devices that are used to measure the flow rate of a certain liquid or gas. They can measure these substances in terms of the volumetric flow rate or the mass flow rate. The volumetric flow rate is generally given in m3/second. The mass flow rate is given in kg/second. Flow meters can be used in many ways. Some of these ways apply to individuals, like the peak flow meter that measures lung capacity and can help asthmatics to know if an attack is likely to occur. However they are most commonly used in industry, notably in machines or processes that require precise amounts of a certain gas or liquid to be applied or added during the manufacturing of an item. This article will cover how some flow meters work. Flow meters are generally classified by the principal that governs their operation or possibly by their applications. For instance, mass flow meters measure the flow rate of a medium in terms of it's mass. The Coriolis flow meter is a point in case of a principle giving it's name to the type of flow meter. The Coriolis effect is the force exerted on a liquid moving in a circular motion. In the flow meter this is done by vibrating the pipes that the liquid passes through. The vibrations (or waves) that are created in the pipes are changed when the liquid passes through them. By knowing the changes in the wave vibrations you can work out the flow rate of the liquid. Ultrasonic and Doppler shift flow meters also use the changes caused to sound waves to correlate a rate of flow for the medium passing through the meter. For an ultrasonic flow meter, flow rate is measured by contrasting the measurements of two ultrasonic waves. These two waves are set off at the same time as each other but from different directions. Receivers at opposite ends of the pipe record the sound waves. One pulse of ultrasonic wave is sent off in the direction of the flow while the other is in the opposite direction. Provided some information is known about the type of pipe used and a few constants for the liquid or gas, then the flow rate can be determined from the time difference of each wave. Doppler shift meters use a sound wave that bounces off matter in the medium passing through the pipe. Due to the Doppler effect, the frequency of the waves changes when it strikes a moving object. This change in the frequency can be used to determine the flow rate of the medium passing through the pipe. A variable area flow meter is a more straightforward meter. It consists of a calibrated tube in which a liquid or gas passes through. In the tube is a float that is displaced by the substance. The reading on the calibrated tube is a correlation of the flow rate of the substance. The peak flow meter uses this principle to measure the flow rate of the lungs when person exhales. About the Author: Get more information on how do flow meters work and details about all types of flow meters at http://www.flowmetermatters.com. Kindly provided by MoneyHunter.org You are welcome to use this article on your own website, if you include the link just before this text. |
Members : 2608
Content : 2691
Web Links : 1
Content View Hits : 255622
Content : 2691
Web Links : 1
Content View Hits : 255622