Turbine flow meters measure volumetric flow by detecting the rotation of a rotor within a housing as fluid passes through. They provide accurate, repeatable measurements with a fast response time. To ensure high accuracy, turbine meters must be calibrated using a positive displacement calibrator that can achieve errors of 0.05% or less. Viscosity affects turbine performance, so meters should be calibrated at the operating viscosity or equipped with technology to correct for viscosity and density variations caused by temperature changes. With proper calibration and correction methods, turbine meters can accurately measure varying flows.
Overview of Badger Meter's Flo-tech range of hydraulic turbine flow meters. Flo-tech products are used in hydraulic testing and analysis and on equipment in a variety of industries, including; agriculture, automotive, construction, forestry, marine and mining.
In this presentation you know about turbine flow meter and how it works. We are providing business directory of turbine flow meter manufacturers and suppliers.
The company stands tall as an Exporter and Supplier of Liquid Turbine Flow Meters in New Delhi. The Liquid Turbine Flow Meters, offered by the company, are known for their corrosion resistant properties and superior quality. The Liquid Turbine Flow Meters provide hassle-free performance and high durability. The Liquid Turbine Flow Meters are demanded in various sectors
Details For Liquid Turbine Flow Meters
Rotational speed proportional to the velocity of the fluid
Truly represents the volume of the fluid flowing through the line
Exceptional performance
Corrosion resistant and highly durable
Specifications
Size 4"~20"
Temperature 20C~120C
Output 4~20mA DC and Pulse(Standard)
Accuracy +/-1.0%
Connection Screwed or Flange
Power Supply AC 85~230V, 50/60Hz or DC 24V or Battery (3 year)
Operating Temperature -20 ~ 120 Deg C
Ambient Temperature -20 ~ 50 Deg C
Accuracy ±1.0 %, ±± 0.5%
Output Signal 4~20mA DC and Pulse (Standard)
Display L C D 2 Line x12 character (Rate Flow /Total Flow)
Service Clear Liquid, Gases ,Air, solvent.
Flange Screwed and Flange (As per standard)
Enclosure IP67,IP65
A device which is used to measure the volume or mass of a gas or liquid is called as a flow meter. Based on which industry its used in, they are called by various names such as flow indicator, flow rate sensor, flow gauge, liquid meter etc. Irrelevant of which industry they are used in, they all are used to measure flow. Flow meters are also used to measure rivers or streams, or any other open channels.
Overview of Badger Meter's Flo-tech range of hydraulic turbine flow meters. Flo-tech products are used in hydraulic testing and analysis and on equipment in a variety of industries, including; agriculture, automotive, construction, forestry, marine and mining.
In this presentation you know about turbine flow meter and how it works. We are providing business directory of turbine flow meter manufacturers and suppliers.
The company stands tall as an Exporter and Supplier of Liquid Turbine Flow Meters in New Delhi. The Liquid Turbine Flow Meters, offered by the company, are known for their corrosion resistant properties and superior quality. The Liquid Turbine Flow Meters provide hassle-free performance and high durability. The Liquid Turbine Flow Meters are demanded in various sectors
Details For Liquid Turbine Flow Meters
Rotational speed proportional to the velocity of the fluid
Truly represents the volume of the fluid flowing through the line
Exceptional performance
Corrosion resistant and highly durable
Specifications
Size 4"~20"
Temperature 20C~120C
Output 4~20mA DC and Pulse(Standard)
Accuracy +/-1.0%
Connection Screwed or Flange
Power Supply AC 85~230V, 50/60Hz or DC 24V or Battery (3 year)
Operating Temperature -20 ~ 120 Deg C
Ambient Temperature -20 ~ 50 Deg C
Accuracy ±1.0 %, ±± 0.5%
Output Signal 4~20mA DC and Pulse (Standard)
Display L C D 2 Line x12 character (Rate Flow /Total Flow)
Service Clear Liquid, Gases ,Air, solvent.
Flange Screwed and Flange (As per standard)
Enclosure IP67,IP65
A device which is used to measure the volume or mass of a gas or liquid is called as a flow meter. Based on which industry its used in, they are called by various names such as flow indicator, flow rate sensor, flow gauge, liquid meter etc. Irrelevant of which industry they are used in, they all are used to measure flow. Flow meters are also used to measure rivers or streams, or any other open channels.
In this presentation how flow rate, pressure, temperature and level in tank measure in refinery or any industry with different instrument are discussed.
raoid transverse and feed circut mostly used where two different speeds for operations are needed. example like punch and press, drill etc.
here the main components are reservoir tank, feed pump, one directional flow control valve, 2 DCV (3/2 & 4/3) and double acting cylinder.
System Components, Hydraulic Oils, Fluid Properties and FilterRAHUL THAKER
System Components, Hydraulic Oils, Fluid Properties and Filter:
Hydraulic & Pneumatic Symbols as per ISO/ANSI, Types, Properties, physical characteristics & functions of hydraulic Oils, Classification- Mineral based, Fire resistant& Biodegradable Oils, Filters, Contaminations, location of filter
Hydraulic System :- A hydraulic system is a system that uses pressurized hydraulic fluid to power hydraulic machinery.
Pneumatic System :- In Pneumatic system Compressed air is Used instead of Liquid
Numerical analysis for two phase flow distribution headers in heat exchangerseSAT Journals
Abstract A flow header having number of multiple small branch pipes are commonly used in heat exchangers and boilers. In beginning the headers were designed based on the assumption that the fluid distribute equally to all lateral pipes. In practical situation the flow is not uniform and equal in all lateral pipes. Mal distribution of flow in heat exchangers significantly affects their performance. Non-uniform flow distribution from header to the branch pipes in a flow system will lead to 25% decrease in effectiveness of a cross flow heat exchanger. Mal distribution of flow in the header is influenced by the geometric parameters and operating conditions of the header. In this work the flow distribution among the branch pipes of dividing flow header system is analyzed for two phase flow condition. In the two phase flow condition, the effect of change in geometric cross sectional shape of the header (circular, square), inlet flow velocities are varied to find the flow mal distribution through the lateral pipes are investigated with the use of Computational Fluid Dynamics software. Keywords: circular, square headers and Computational Fluid Dynamics software. (CFD)
In this presentation how flow rate, pressure, temperature and level in tank measure in refinery or any industry with different instrument are discussed.
raoid transverse and feed circut mostly used where two different speeds for operations are needed. example like punch and press, drill etc.
here the main components are reservoir tank, feed pump, one directional flow control valve, 2 DCV (3/2 & 4/3) and double acting cylinder.
System Components, Hydraulic Oils, Fluid Properties and FilterRAHUL THAKER
System Components, Hydraulic Oils, Fluid Properties and Filter:
Hydraulic & Pneumatic Symbols as per ISO/ANSI, Types, Properties, physical characteristics & functions of hydraulic Oils, Classification- Mineral based, Fire resistant& Biodegradable Oils, Filters, Contaminations, location of filter
Hydraulic System :- A hydraulic system is a system that uses pressurized hydraulic fluid to power hydraulic machinery.
Pneumatic System :- In Pneumatic system Compressed air is Used instead of Liquid
Numerical analysis for two phase flow distribution headers in heat exchangerseSAT Journals
Abstract A flow header having number of multiple small branch pipes are commonly used in heat exchangers and boilers. In beginning the headers were designed based on the assumption that the fluid distribute equally to all lateral pipes. In practical situation the flow is not uniform and equal in all lateral pipes. Mal distribution of flow in heat exchangers significantly affects their performance. Non-uniform flow distribution from header to the branch pipes in a flow system will lead to 25% decrease in effectiveness of a cross flow heat exchanger. Mal distribution of flow in the header is influenced by the geometric parameters and operating conditions of the header. In this work the flow distribution among the branch pipes of dividing flow header system is analyzed for two phase flow condition. In the two phase flow condition, the effect of change in geometric cross sectional shape of the header (circular, square), inlet flow velocities are varied to find the flow mal distribution through the lateral pipes are investigated with the use of Computational Fluid Dynamics software. Keywords: circular, square headers and Computational Fluid Dynamics software. (CFD)
A Smart Flow Measurement System Adaptive to Different Variation Using Ultraso...Sheikh R Manihar Ahmed
This Paper Explain the Design of a Smart Flow measurement Technique using Ultrasonic Flow Meter for custody transfer quality. The objective of the work are; (i) to extend the linearity range of measurement to 100% of the input range, (ii) to make the measurement system adaptive to variations in pipe diameter, liquid density, and liquid temperature. An Accurate flow measurement is an essential requirement both from qualitative and economic points of view. Among the non contact type of flow measurement, ultrasonic flow measurement is widely used to measure flow, because of its advantage like high resolution and less interference of noise on output. However, non linear characteristics of Ultrasonic flow meters have restricted its use. An optimal Computational Logic is considered by comparing various schemes and algorithms based on minimization of Mean Square Error and Regression close to one. The output of ultrasonic flow meter is frequency. It is converted to voltage by using a frequency to voltage converter. An optimal Computational logic block is added in cascade to frequency to voltage converter. This arrangement helps to linearise the overall system for 100% of full scale and makes it adaptive to variations in pipe diameter, liquid density, and liquid temperature. Since the proposed Smart flow measurement technique produces output which is adaptive to variations in pipe diameter, liquid density, and liquid temperature, the present technique avoids the requirement of repeated calibration every time there is change in liquid, and/or pipe diameter, and/or liquid temperature. The results show that proposed measurement technique achieves the objectives quite satisfactorily.
At the basis of a good flow measurement is a properly calibrated flowmeter. Field calibration of flowmeters is far from straightforward and its impact on the operation of a metering station in the field can be considerable. One of the options is including a fixed pipe prover in the metering system. For an article that appeared in this month’s edition of World Pipelines, Eveline Janse interviewed Erik Smits (VSL) and Shukur Aghazadeh (AzMETCO), who shone their light on various methods for the calibration of the pipe provers, their advantages and drawbacks.
Importance of three elements boiler drum level control and its installation i...ijics
Conversion of water into steam is the primary function of a utility boiler. The steam pressure is used to turn
a steam turbine thus, generating electricity. Within the boiler drum there exists a steam/water interface.
Boiler steam drum water level is one of the important parameters of power plant that must be measured
and controlled. For safe and efficient boiler operation, a constant level of water in the boiler drum is
required to be maintained. Too low water level may cause damage boiler tube by overheating. On the other
hand too high drum water level leads to improper function of separators, difficulty in temperature
controlling and damage in superheater tubes. Turbine may also be damaged by moisture or water
treatment chemicals carryover. The amount of water entering the boiler drum must be balanced with the
amounts of steam leaving to accomplish the constant water level in the drum. Therefore it is extremely
important to have the knowledge of the operating principles, installation requirements, strength and
weaknesses of drum water level control system. Ignoring these considerations can result in misapplication,
frequent maintenance, unsafe operation and poor instrument as well as system performance. In this paper
design aspects and installation requirements of boiler drum level control are discussed for safe and
economic operation.
Liquid Level Estimation in Dynamic Condition using Kalman FilterIJERA Editor
The aim of this paper is to estimate true liquid level of tank from noisy measurements due to dynamic conditions
using kalman filter algorithm. We proposed kalman filter based approach to reduce noise in liquid level
measurement system due to effect like sloshing. The function of kalman filter is to reduce error in liquid level
measurement that produced from sensor resulting from effect like sloshing in dynamic environment. A prototype
model was constructed and placed in dynamic condition, level data was acquired using ultrasonic sensor to
verify the effectiveness of kalman filter. The tabulated data are shown for comparison of accuracy and error
analysis between both measurements with Kalman filter and statistical averaging filter. After several test with
different liquid levels and analysis of the recorded data, the technique shows the usefulness in liquid level
measurement application in dynamic condition.
Liquid ultrasonic flow meters (LUFMs) continue to gain
popularity in petroleum measurement with the promise
of high accuracy and low maintenance. These are favorable features, but because of the high volume and value
of petroleum products, buyers and sellers must have a
high level of confidence in the accuracy of measurement. This assurance in custody transfer measurement
is gained by adherence to the standards, procedures
and methods that define the measurement process
The primary function of a utility boiler is to convert water into steam to be used by a steam turbine/ generator in producing electricity. The boiler consists of a furnace, where air and fuel are combined and burned to produce combustion gases, and a feedwater tube system, the contents of which are heated by these gases.
Improving Energy Efficiency of Pumps and Fanseecfncci
Pumps and Fans are energy consuming equipment that can be found in almost all Industries. Therefore, it is important to check if they are running efficiently. This presentation give an overview about energy saving opportunities in pump and fan equipment. It was prepared in the context of energy auditor training in Nepal in the context of GIZ/NEEP programme. For further information go to EEC webpage: http://eec-fncci.org/
This presentation discusses:
- Best practices regarding the need to ensure that all transformers used for metering circuits are properly sized
- The ability to optimize revenue regardless of customer usage over time
- Best practices to ensure that transformers and meters have been installed correctly in the field and continue to perform in the same fashion
- Best practices for certifying the accuracy class of the transformers and how to best set up a shop testing and field testing/verification program.
- What the costs of implementing such a system and what the costs of not implementing such a system can be.
Similar to Selection and Calibration of a Turbine Flow Meter (20)
PID is short for "proportional plus integral and derivative control", the three actions used in managing a control loop. Process loop controllers use one, two or all three of these to optimally control the process system. PID control is used in a wide variety of applications in industrial control and process system management.
Courtesy of Eurotherm. Eurotherm offers a wide range of single & multi-loop PID controllers.
Smokeless Flares
Smokeless flares incinerate flammable hazardous vent gas with the assistance of supplemental high-velocity air or steam to prevent the formation of soot or smoke. Excessive injection of air or steam reduces combustion efficiency, resulting in the release of hazardous VOC gases. Meanwhile, inadequate injection of air or steam results in the formation of undesirable soot and smoke. Although modern flares are designed for high flow rates associated with an emergency condition, they most commonly operate at high-turn-down, low-flow rates, making it challenging for the flare to operate at optimal combustion efficiency.
Pilot Monitor
Flammable vent gases are ignited by a pilot flame when released into the atmosphere by refineries, natural gas processing plants, and petrochemical plants. The proper incineration of these gases is a critical safety and environmental concern. Therefore, it is essential to confirm that the pilot is lit at all times. Monitoring via a thermocouple is common, however, failures frequently occur and replacements can require costly process shutdowns. Remote sensing IR technology (PM) is the superior alternative.
Flame Intensity Monitors
Williamson Flame Intensity Monitors (FI) are the single-wavelength sensors of choice for a variety of flare applications where the more sophisticated dual-wavelength flare products are not appropriate or are not required.
Some materials can be difficult or near impossible to measure with precision using single-wavelength or ratio pyrometers because of their complex emissivity characteristics. These types of materials are called non-greybody materials and their emissivity varies with wavelength.
Multi-wavelength pyrometers use application specific algorithms to characterize infrared energy and emissivity across the measured wavelengths to accurately calculate both the actual temperature and emissivity of these complex non-greybody materials.
The 3000 series gives you high accuracy, fast response time and low temperature drift – without compromise. All 6 mm devices can be mounted on a standard DIN rail or power rail with no air gap separation.
Bronkhorst has over 35 years experience in designing and manufacturing precise and reliable measurement and control equipment and the widest range of mass flow and pressure meters and controllers available on the market.
Bronkhorst offers innovative solutions for many different applications across a great many different markets, and has a particular strong wealth of knowledge and reputation within the plastics and rubber market.
The Coriolis measuring principle refers to the effect that a moving mass has on a body in a rotating frame of reference. The moving mass exerts an apparent force on the body, causing a deformation. This force is called the Coriolis force. It does not act directly on the body, but on the motion of the body. This principle is used in Coriolis flowmeters.
AP Tech is a manufacturer of gas handling components – primarily pressure regulators and valves. AP Tech’s competitive advantage are products that deliver specialty gases for high purity through ultra high purity applications. Starting from the source vessel to point of use and into the process tool or equipment itself, AP Tech products are known to deliver gases with uncompromising quality, performance and reliability.
The L100 Bubble-Tube Level System is a fully self contained instrument, requiring only connections to air or gas supply, dip tube and electrical power source to provide precise level indication. Because only the stationary dip tube and the purge gas come in contact with the liquid, this system is ideal for applications involving hazardous locations or liquids which are highly corrosive, viscous, hot, (molten metal), explosive, slurry type or foodstuff.
For applications where rapid transition from open to closed positions is warranted, the Mark 76 is a solid choice. Designed with a short stroke and straight through fluid path, the Mark 76 also incorporates other features to assure good service for process operations using on/off control.
Tek-Trol provides process measurement and control products for Flow, Level, Temperature and Pressure measurement and Control Valves and Analyzers systems for the Process, Power and Oil and Gas Industries.
EL-FLOW Prestige is the next generation of Bronkhorst Mass Flow Meters / Controllers for gases. Nearly all core components have been redesigned and many improvements and innovations have been incorporated. With this new series Bronkhorst introduced the “Differential Temperature Balancing” technology, ensuring a superb sensor stability.
Each ReFlexIO unit allows you to connect (2) Analog Inputs and (2) Digital Inputs which are wirelessly transferred to (2) Analog Outputs and (2) Digital Outputs on the other end. The 2 ReFlexIO 'paired' units work bi-directionally, so it's possible, for example, to turn on a relay (digital input to digital output on the other end) and get a signal back (digital input to sense replay closure returned to digital output on the original sending unit) to turn on a light telling you that the relay is indeed on.
The T2750 PAC hardware provides high-performance control with cost-effective redundancy options in a versatile modular system. Powerful instruments, the control units, and the I/O system form the basis of a complete distributed control and recording environment. This environment is capable of continuous analog, logic, sequential control, batch management, secure data recording at point of measurement, and setpoint programming.
The T2550 PAC is a high performance solution offering extremely cost effective redundancy options - making high availability viable for more of your process.
The control unit and I/O system form the basis of a complete distributed control and recording environment capable of continuous analog, logic and sequential control combined with secure data recording at point of measurement - all designed to maximize Return on Investment (ROI) from your process.
ControlAir Inc. is a leading manufacturer of precision air pressure regulators, I/P transducers, E/P transducers, P/I transducers, valve positioners, air relays, volume boosters, air filter regulators and frictionless diaphragm air cylinders.
The LowFlow JRDL Series line of diaphragm sensed, high pressure regulators have the ability to handle very high pressures and very low flows. These valves are typically used in research and sampling systems for general, corrosive and specialty gas and liquid service. Typical applications include gas chromatography and flame ionization detectors, as well as other industrial controls.
The Model TCL measures total chlorine in water, and is ideal for seawater chlorine analysis applications. The system consists of a sample conditioning unit, a sensor, and transmitter
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Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
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When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
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and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
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CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
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Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
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Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
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Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
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Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
1. 1 of 9
Selection and Calibration of a Turbine Flow Meter
Turbine flow meters have been an effective flow measurement technology for
many years. Advancements in other measuring technologies in recent years
have provided many options when selecting a meter for a flow measurement
application. This has the benefit of allowing the user to select the measuring
technology that provides the optimum characteristics for the specific application.
The downside of all these measurement options is the user must have a
significant understanding of many technologies in order to make the best
educated decision when selecting the meter.
The intent of this paper is to provide the reader with a basic understanding of the
operational characteristics and calibration methods of turbine flow meters. The
information provided is targeted at liquid meter applications. Turbine meters are
also successfully used in gas applications. The operational characteristics of gas
meters are basically the same as liquid meters, however the calibration methods
and procedures are worthy of a paper specific to gas applications and will not be
address at this time.
Turbine meter operation
A turbine flow meter is a volumetric flow metering device. The meter consists of a
rotor and bearing assembly suspended on a shaft, which is mounted to a support
device. This assembly is mounted inside a housing with a known internal
diameter. (See figure 1) As fluid passes through the flow meter housing the rotor
will spin at a rate proportional to the volume of liquid passing through the
housing. A magnetic or modulated carrier pick-off sensor is used to detect the
passage of each rotor blade and generate a frequency output. The frequency
output can be read directly with the end users electronics or further processed to
convert to an analog output, linearized or compensated for temperature
variations.
There are several characteristics of turbine flow meters that make them an
excellent choice for some applications. The flow sensing element is very compact
and light weight compared to various other technologies. This can be
advantageous in applications where space is a premium. Examples of these
applications are; on board aircraft, marine vessels and motor vehicles; in subsea
control pods and ROVs used in the oil and gas industry; and on R&D and
production test equipment. The speed of response of a turbine is dependent on
the size and mass of the rotor and the fluid being measured. Typically the
response time is very fast, on the order of 5 ms. When correctly calibrated by a
quality laboratory, turbines have a repeatability of +/-0.05% and can achieve an
overall accuracy of +/-0.25% of reading over a wide turndown. A feature which is
often not associated with turbines, is the ruggedness of the design. Turbines are
unaffected by vibration. They are often used on aircraft, missiles, military
2. 2 of 9
weapons delivery systems and racing vehicles of various types. High shock
designs for the turbine are also available making them very resistant to hydraulic
fluid shock forces.
Calibration Systems
With any flow measurement instrument, the overall system accuracy achieved
can be no greater than the equipment used to perform the calibration. There are
several possible calibration techniques, positive displacement, time weigh, field
prover, and the old stand by, bucket and stop watch. The technique that will be
discussed here is the positive displacement calibrator. (See figure 2) A positive
displacement calibrator utilizes a precision machined measurement chamber, or
flow tube, that houses a piston. This piston acts as a moving barrier between the
calibration fluid and the pressurizing media used to move the piston. Attached to
the piston is a shaft that keeps the piston moving in a true path and provides the
link between the piston and the translator. The translator converts the linear
movement of the piston through the precision flow chamber into electrical pulses
that are directly related to the displaced volume. Calibrators of this style can be
directly traceable to the National Institute of Standards and Technology via water
draw validation. Total accuracy of this type of calibrator is conservatively
specified at 0.05%.
The calibration data that is recorded and normally presented in tabular format
consists of: The frequency output of the meter at each data point, the
corresponding fluid flow rate for each frequency and the K-Factor, or pulses per
unit volume of fluid for each data point. Also presented for use when temperature
compensation is required is the ratio of meter frequency divided by the kinematic
viscosity of the calibration fluid. Typically ten data points are taken throughout the
repeatable flow range of the meter however up to fifty data points can be taken if
desired. The more data points taken, the better defined the meter calibration
curve will be.
Typically a turbine meter will have a “normal 10:1” flow range where the K-Factor
remains linear and the “extended” flow range where the meter maintains the
specified repeatability, however the linearity of the K-Factor will be reduced. (See
figure 3) With multiple calibration points to define the curve and processor based
electronics to perform curve fitting calculations, outstanding accuracy can be
maintained throughout the entire extended flow range. Care must be taken when
using turbines with a single average K-Factor. When using only a single point
from the calibration curve, the variation in linearity with flow rate is unknown.
Accuracy of the reading will be reduced as the flow rate of the meter varies, and
because the actual calibration curve is unknown, the amount of error will not be
known.
3. 3 of 9
Viscosity Effects
A factor that must be taken into account when applying a turbine flow meter is
the operating kinematic viscosity of the fluid to be measured. Viscosity is the
characteristic of a fluid which causes it to resist flow. The higher the viscosity, the
greater resistance to flow the fluid will have. Turbines are designed to measure
the velocity of the fluid passing through it, however the viscosity of the fluid also
has an effect on the rotational speed of the rotor. Figure 3 was performed at 1
centistoke, or water. Water is a standard calibration media that many flow meter
manufactures use. The media is low cost, easy to work with, none hazardous
and easy to dispose of. Applying the turbine in an operating viscosity different
from what the meter was calibrated at will create an offset in the calibration
curve. Figure 4 demonstrates the effect of viscosity variations from 1 to 100
centistoke on a ” meter. The amount of shift in the K-Factor curve can be
significant depending on the viscosity variation. The amount of offset is also
dependant on the flow rate of the meter. The lower the flow rate within the
capable range of the meter, the greater the offset. In this example there is
approximately 3% difference between the 1 centistoke and 100 centistoke curve
at 5 GPM and 57% offset at 0.05 GPM. A common request is to provide a
correction factor that can be applied to a calibration at one viscosity, to obtain
corrected data at a different operating viscosity. As can be seen from the
nonlinear nature of the offset to the curve, a single correction factor is not
possible. In order to maintain the highest accuracy the flow meter should be
calibrated at the same viscosity as the fluid it will be used to measure.
Real Time Correction for Viscosity and Density Variation
In many applications the viscosity of the fluid to be measured will change during
the measurement period. In some situations the viscosity and density of the
measurement fluid changes due to a physical change to the mixture of the fluid.
In these situations the turbine meter will not be the best choice for a
measurement instrument. However in most applications the density and viscosity
is changing due to variations in the operating temperature of the fluid. In a
Newtonian fluid as the operating temperature of the fluid increases, the kinematic
viscosity and density decreases. In these situations the turbine can be an
effective measurement instrument when properly calibrated. In order to correct
for viscosity changes the relationship of temperature verses viscosity must be
known for the fluid and the operating temperature range of the measurement
must be known. With the operating kinematic viscosity range known, the turbine
meter is calibrated at multiple viscosities covering the operating range. The meter
will require a calibration for every factor of ten that the viscosity changes. For
example a fluid with an operating range of 1 to 100 centistokes would require a
multiple point calibration at 1, 10 and 100 centistokes. This data is then
presented on a semi log plot called a Universal Viscosity Curve (UVC). The UVC
is formed by plotting the meter K-Factor on the linear scale and frequency
4. 4 of 9
divided by kinematic viscosity on the logarithmic scale. (See figure 5) The result
of this plot is one continuous curve covering the range of possible meter
frequencies and viscosities.
Real time volumetric flow is obtained by measuring the operating temperature
and addressing a temperature verses viscosity look up table to determine the
operating kinematic viscosity. The frequency is measured directly from the flow
meter and divided by the kinematic viscosity. This ratio of frequency and viscosity
is used to determine the correct K-Factor for the specific operating temperature
and viscosity. One additional factor that should be taken into account to obtain a
temperature corrected flow rate, is the expansion or contraction of the meter
housing due to the temperature variation from the calibrated condition. This
correction is based on the thermal coefficient of expansion of the flow meter
housing and can be accomplished through the use of two dimensionless
numbers, Strouhal and Roshko. The Roshko correction is applied to the
frequency/viscosity parameter and the Strouhal correction is applied to the K-
Factor parameter. A full derivation of these parameters can be found in a paper
“The Characterization of a Piston Displacement-Type Flowmeter Calibration
Facility and the Calibration and Use of Pulse Output Type Flowmeters” by Dr.
G.E. Mattingly with the National Institute of Standards and Technology.
In cases when a mass flow rate is desired over a volumetric measurement one
additional table can be added to the electronics to determine the temperature
verses density of the fluid. The corrected volumetric flow rate can then be
multiplied by the fluid density at the operating temperature, achieving a real time
corrected mass flow rate. Figure 6 is a block diagram indicating the temperature
correction for viscosity, housing dimensional changes and density that would be
performed by the manufacture supplied flow computer or within the end users
data acquisition system.
Summary
Turbine flow meters are a tried and proven technology that offer the benefits of
minimal size and weight, high accuracy and fast speed of response, rugged
construction and a favorable cost compared to other measurement technologies.
When specifying a flow measurement technology for an application the user
needs to be aware of the benefits and limitations of the various technologies in
order to make the best decision. The intent of this paper was to show that when
properly calibrated, turbine meters can provide an accurate option for
applications of various viscosities and in situations with viscosity and density
changes due to temperature variation.
5. 5 of 9
Figures
Figure 1
End Fitting
Housing
Rotor
Cone
Support
Retaining Ring
Pickoff Well
9. 9 of 9
Figure 6
Copyright 2007 Flow Technology, Inc. All rights reserved.
Flow Technology
8930 South Beck Avenue, Suite 107, Tempe, AZ 85284 USA
Phone: 480.240.3400, Fax: 480.240.3401
Web: http://www.ftimeters.com
E-mail: ftimarket@ftimeters.com