The test of move meter measurement is conducted to introduce the students to the three different types of widely used flow meter in the industry. The three circulation meters involved in the experiment are Orifice move meter, Magnetic stream meter, and Coriolis circulation meter. It really is aimed to help the students to comprehend the typical ways of flow measurements associated with an incompressible liquid, in which in this case is normal water.
In the industries, many different circulation meters are used to measure different types of essential fluids. The decision of the flow meter might rely upon many factors like the heat range, pressure conditions, denseness, viscosity, conductivity or even the conditions of the liquids such as slurries or normal substance. The selection of the kind of flow meters might also be accounted to the reliability of the move meters itself.
Therefore, the experiment will serve to expose the students to the types of circulation meters available in the market and to create them to the essential working system of the called flow meters. They might be asked to select a suitable flow meter for the plant or industry when they are in the task environment. Therefore, the basic knowledge of the stream meters as well as their mechanisms and working rules is important to become technically sound in the work environment.
There are various kinds of flow meters available for sale. In order to select the correct move meter for a use, it's important to review the characteristics of each and every of the circulation meters as well as their working system.
For an orifice circulation meter or also known as differential pressure stream meters, it uses the idea of pressure drop to measure the flow rate of your fluid. If the fluid flows into a tube of an different size, its speed changes so is its pressure. For example, when it goes into a pipe of an smaller size, the fluid's velocity increases and it accelerates. In effect of this, the pressure of the fluid decreases matching to Bernoulli's law. Because of this, a differential pressure is created or even more specifically, a pressure drop. The magnitude in the pressure drop establishes the speed of the liquid that raises when it gets into the smaller tube. The next formulae can be used to calculate the guidelines for the test:
V = k (h/D)0. 5
Q = kA(h/D)0. 5
W = kA(hD)0. 5
Where h: pressure differential
V: flow factor velocity and the
Q: the volumetric flow
W: mass flow
K: release coefficient of the element
As for a magnetic stream meter, it utilizes the idea of conductivity to measure the circulation rate of the liquid. When a liquid with certain conductivity passes through the magnetic field created by the magnetic move mater, a voltage is induced. It happens therefore of the fluid crossing the magnetic field or flux of the machine. Because of this, a voltage is induced and the magnitude of the voltage produced is proportional to the velocity of the liquid that goes by through the movement meter. Therefore, a measure of the stream rate is possible. That is known as Faraday's rules of electromagnetic induction. The induced voltage can be calculated using the formula:
E=B. v. d.
Where : E = Induced voltage [proportional to speed]
: B = Magnetic flux density
: v = mean vcity of the media
: d = Distance between the sensing electrodes
Figure 1: Magnetic circulation meter Body 2: Cross- section view of any magnetic flow meter
For a coriolis meter, it is also known as inertial movement meter or a mass circulation meter. It measures directly the mass or level of a smooth that passes through the circulation meter. The movement rate is then obtained by dividing it by time in which mass per product time is obtained. For any coriolis stream meter, if the thickness is constant, then the measurement of the move rate is simple whereby it is just the mass as time passes. Yet, in some cases, density changes as the computation might be more complex. A coriolis meter has the ability to measure different kinds of liquids such as liquids, slurries and gases. Inside the tubes due to Coriolis causes, the form of the tube will be deformed and this will cause a vibration. A solution may be used to computate the mass flow.
Where Ku : temp dependent stiffness of the tube
K: a shape-dependent factor
D: the width
: the time lag
: the vibration frequency
Iu: the inertia of the tube
Figure 3: Coriolis Circulation meter
From the data obtained from the experiment, we can compare different types of stream meters that are available on the marketplace. A couple of specifically three types of move meters that people analyze in this test, namely, orifice flow meter, magnetic circulation meter and coriolis circulation meter. The primary observation to be done through this experiment is to regulate how the stream rate an incompressible liquid is measure, where in cases like this is drinking water.
For the orifice stream meter or also known as as differential pressure circulation meter, we can watch a craze in the readings. At the beginning of the test, a circulation rate of 10L/min is defined, accompanied by 15L/min and finally 20L/min. The accuracy and reliability of the reading compared to the calculated value is relatively high. However, a style is witnessed. The precision is higher at circulation rate of 10L/min, reduces for the 15L/min and is the highest for the 20L/min movement rate. This correctness can be triggered by the mistakes present in performing the experiment. For a orifice move meter, a pressure drop is produced when the smooth passes via a barrier or restriction. If the substance passes through the pipe of smaller diameter, it accelerates with a higher velocity. Matching to Bernoulli's Law, when a substance accelerates, its pressure decreases and for that reason creates a pressure drop. An orifice circulation meter's accuracy is normally ±0. 2% of the calibrated course. So, at the reduced end of the 10:1 flow range (10% flow), which corresponds to a differential pressure selection of 100:1, the flow meter would have one of ±20% of the actual reading. Because of this, differential producing circulation meters is limited to used in a smaller range or a minimal flow.
As for the magnetic stream meter, a same trend is noticed whereby the reliability of the reading starts off high for movement rate of 10L/min, and then drops for stream rate of 15L/min which is highest for the 20L/min flow rate. As for a magnetic circulation meter, it can be considered as an excellent flow meter since it measures a wide range of liquid measurements with low conductivities. It generally does not use the concept of pressure drop and for that reason, pressure drop in this case is negligible. The idea behind the stream measurement because of this device is Faraday's Rules of Electromagnetic induction. When a conductor passes through the magnetic field, a voltage will be induced and the strength of the voltage is proportional to the speed of the moving smooth. Basically, the faster the fluid moves, the bigger the voltage induced which implies or informs the experimenter on the movement rate of the substance. This measuring device is in addition to the viscosity, denseness, pressure & temperatures of smooth. Its accuracy is approximately ±0. 5% of the movement rate.
Again for the coriolis flow meter, a same tendency is witnessed. The accuracy and reliability is highest for stream rate of 20L/min, accompanied by 10L/min and lastly 15L/min. A coriolis move meter measures the amount or quantity or mass of the liquid that flows through it. The stream rate is then obtained as the mass per device time, for instance kg/s. Similar to a magnetic stream meter, a coriolis stream meter is not influenced by the changes in pressure, temperature, viscosity and density When a liquid enters the tube, a push is exerted to cause the tube to vibrate, the pipe will twist or rotate consequently of the acceleration performing in the contrary directions. The advantage of a coriolis circulation meter is that it measures immediately the move rate of any fluid without considering the factors of heat range, pressure or even the viscosity of the liquid. The correctness of the coriolis circulation meter is approximately ±0. 1%.
Base on the test, there are several mistakes affecting the results of the experiment:
- Fluctuating move rate results the difficulty to learn the level effectively especially during original area of the experiment because this particular circulation is not stable and enough time keeper might not start enough time accurately when the water level reaches 0L/min.
- The fluctuating of the stream rate also helps it be difficult to set up the move rate of the water in constant, in particular when we desire a frequent value at 10L/min, 15L/min and 20L/min.
- The start of time-keeping is not synchronized and might not be effectively started when the level of reservoir reaches 0L/min due to the different response time of the experimenter.
- Parallax error occurs when reading this tank level, anticipated to restrictions like elevation of the reader in which some may be too tall and in any other case.
There are several methods that can triumph over or lessen the mistakes:
- The problem due to the fluctuating circulation of water can be fixed by repeating the experiment and obtaining an average of the measurements.
- To decrease the parallax error, ensure that this level is parallel with your eyes.
- To raise the accuracy of your time, use digital stopwatch alternatively than analog stop watch or other methods.
In conclusion, coriolis flow meter has the highest accuracy, followed by the magnetic flow meter, and last in the order is orifice movement meter. The aim of the test which is to compare the accuracy and reliability of each move meter as well concerning study the device of the flow meters is achieved. The usages of the flow meters are different on the market. Selecting flow meters is dependant on the specification that can match the dependence on the industry.