Level Measurement
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Level Measurement |
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Austral-Powerflo Solutions sells, manufactures and supports a wide range of high quality Engineered Control Valves, Safety Devices and Process Instrumentation serving virtually every industry in which liquids or gases are controlled or measured. Their philosophy is “Smart Service” which means that deliverables must incorporate a strong engineering capability, a technical understanding of the current Australian Standards, competent contract management and proficient after-sales support. Magnetrol’s level and flow controls transform industrial process measurement. Their conventional and electronics-based instruments make measurement more intelligent, more reliable and far more simplified to set up and operate than was ever possible.
Have
a question on or need to purchase quality Level Instrumentation? Our
Sponsors Austral
Powerflo Solutions are Experts in this area!
Contact
them here.
Just Scroll down to get to some great technical data on Level Instrumentation
Magnetrol have a Comprehensive Library of Level Applications which detail possible level measurement solutions - so if you need help in this regard just hit this link.
3.11
Level Measurement by IndustryMagnetrol have a Comprehensive Interactive List of Level Solutions by Industry.
RF
Capacitance- The basics-thanks to our sponsors Austral
Powerflo Solutions and Magnetrol
Other Links
RF/Capacitance
Level Instrumentation-from omega.com
Electronic
Displacer Transmitter Liquid Level Measurement Basics - A
good introduction from Magnetrol.
Displacer
switch operation - This is based upon simple buoyancy,
whereby a spring is loaded with weighted displacers which are heavier than the
liquid-from Magnetrol.
Dont
take the Risk - Is your Bulk Liquid Storage Tank Protected?-
Do you have bulk liquid storage tanks containing petroleum
products, ammonia, caustic chemicals, acids, ethanol, bitumen, pharmaceuticals,
beverages, tallow where overflow could occur. This article describes how an high
integrity, independent level switch, preferably of different technology to that
used for the tank gauging system, is required to monitor any failure of the auto
tank gauging system and shut down product transfers -thanks to our sponsor Austral
Powerflo Solutions
The Following technical information is
compliments of our sponsors Austral
Powerflo Solutions and Magnetrol
Magnetic
Level Indicators - The Next Generation -
This unit incorporates Magnetrol’s advanced
Eclipse guided wave radar technology with the time
proven and time tested magnetic level indicator. To
date almost 10,000 Eclipse transmitters are working
throughout the world in tough measuring
applications, with most of those being the highly
efficient coaxial probe type. The primary benefit is
that Eclipse does not depend on the MLI float for operation,
as does a magnetostrictive transmitter. Redundant
visual indication and a 4-20 mA signal in
one instrument!
3.11Selecting
the Right Magnetic Level Indicator - Companies in
the process industry need the ability to visually monitor liquid levels in
vessels (boilers, storage tanks, processing units, etc.). Traditionally, armored
glass sight gauges have been used. However, many companies want an alternative
to sight gauges to avoid problems such as breakage, leaks, or bursting at high
pressures and extreme temperatures. In addition, the visibility of the sight
glass can be poor and often affected by moisture, corrosion, or
oxidation.Magnetic level indicators (MLIs) do not have the shortcomings of glass
sight gauges and are suitable for a wide variety of installations.
Float-
Details of float measurement techniques explained
Atlas
MLI vs. Gage Glasses
Evolution
of Magnetic Level Indicators
Replacing
DP Transmitters with Magnetic Level Indicators
MLI
Branch Connection Comparison
- Full-Bore / Full Penetration vs. Extruded Tee - This
application note provides a comparison of Orion’s full-bore/full
penetration (conventional) branch connections and extruded
tee branch connections as used on Magnetic Level
Indicators
External Caged
Floats- the basics
Float
Level Switches - the basics
Magnetic
Level Indicators- the basics
Other Links
Typical Specific
Gravities- from KTek
Resistive
Magnetic Level for LPG tanks - Thanks to Bintech
New
Improvements to Magnetic Level Gauge Technology Yield Increased Control,
Accuracy, Safety and Reliability for Plants that Process and Store Fluids
Thanks to automation.com
10.11Demystifying
Noncontact Gauge Performance Statements
-David W. Spitzer - Currently,
there are at least 30 different methods for stating the performance of
noncontact gauges, making it nearly impossible for users to compare and contrast
level measurement devices against each other. Level measurement systems
perform a relatively basic function — they determine the inventory of a
contained material. But selecting a level measurement instrument is far from
simple, especially when one considers the wide variety of performance statement
methodologies users must decipher when evaluating noncontact level gauges. While
there are many level measurement systems that can gauge the inventory of liquid
in a vessel, the number of viable solutions decreases significantly when the
vessel is agitated and/or operates at high temperatures. Further, foaming and
the effects of filling and emptying the vessel can result in added complication.
Therefore, level measurement applications require careful engineering, which
demands that users have a clear understanding of the actual meaning of different
supplier performance specifications - from Flow Control.
The Following technical information is
compliments of our sponsors Austral
Powerflo Solutions and Magnetrol
Choosing
the Right Guided Wave Radar Product -Kevin
Martyn,
3.11Guided
Wave Radar vs. Differential Pressure Transmitters for Liquid Level Measurement
- Over the years, however, newer level measurement devices have
emerged and are consistently capturing market share from older technologies
which utilize mechanical and pressure-based measurement-including DP
transmitters. Technologies such as Non-Contact Radar, RF Capacitance,
Ultrasonic, Magnetostrictive, and GuidedWave Radar employ the latest
microprocessor-based digital electronics. By incorporating internal diagnostics,
these devices have improved the control, analysis, communication, and overall
reliability of fluid level management systems - from www.controlglobal.com
Eclipse®
GWR vs. RF Capacitance - Boyce
Carsella -Is it time to replace your troublesome RF
Capacitance/Admittance Liquid Level Transmitters?
Non-Contact
Radar Measurement - An
examination of the various types - Kevin Martyn
Radar/Magnetic-
This unit incorporates Magnetrol’s
advanced Eclipse guided wave radar technology with
the time proven and time tested magnetic level
indicator.
Comparison
of Guided Wave Radar against other level Measurement Technologies-
This is a neat comparison tool
Guided
Wave Radar -the basics
Pulse
Burst Radar - The basics
Replacing
Old Technology - Revitalising level measurement accuracy
at a Soviet-era plant
Sanitary
Liquid Level Measurement - Drug-makers are now choosing
solid-state, non-mechanical devices that deliver higher accuracy, require less
frequent calibration, offer enhanced validation schemes, and are installed in
such a way that an instrument failure won’t compromise process uptime or
derail a batch in process.
Gauge
Your Level Instrumentation - Keith Larson - Technology
advances and downtime avoidance steer drug makers toward top-mount,
non-intrusive methods for continuous liquid level measurement.
Level
Indicators Reach New Heights - Exactly how much is
in there? It’s an easy question if you can see into a tank, but what if
you’re basically blind, or your tanks must be sealed? Sure, traditional
solutions may work for awhile, but they’re historically hard to maintain and
sometimes lack accuracy.
Radar
Level Gauges - Frequently Asked Questions - Bob Botwinski
Pulsar
Radar Level Up to the Challenge at Chemical Plant -
This facility offered numerous challenging level measurement applications,
including overfill and spill protection requirements. This is a large 7.0 MB
download.
Upgrading
Level Instrumentation - Field Upgrades aren't always as easy as 1, 2, 3 -
Walt Boyes - Control Magazine
Other Links
Radar
Level Measurement Best Practice - Sarah Parker, Applications Manager, Emerson
Process Management, Rosemount division - The emergence of radar has been an
important advance in the level measurement field. Radar represents a cost
effective, accurate solution that is immune to density and other process fluid
changes as well as most vapour space conditions - from Emerson Process
Management and the Read-Out Instrumentation Signpost.
10.11Non-Contact
Radar Level Measurement - David W. Spitzer - Some basic technical
information.
Innovation
in Level Measurement - End-of-Probe Algorithm - From automation.com
Guided
Wave Radar Transmitters:Meeting the Challenge for Level-Detection Under Harsh
Conditions- From automation.com
The Following technical information is
compliments of our sponsors Austral
Powerflo Solutions and Magnetrol
Principal
of Operation
Ultrasonic
Contact - The basics
Ultrasonic
Non-Contact - The basics
Flexibility,
Powerful Performance from Magnetrol Ultrasonic -
Magnetrol’s new Echotel Model 355 Transmitter Can Handle Applications That
Were Unthinkable Just a Few Years Ago - As advances in digital signal processing
and low-power operation circuits make their way into the design of field
instruments, ultrasonic level transmitters have gotten smarter and more
effective. Thanks to www.controlglobal.com
Other Links
Sound
Advice - The measurement of level and flow is
8.10
No
Contact Means Ultra Level Measurement
- In level-measuring applications where it’s undesirable to have contact
of the measuring instrument with the liquid in the process, a sonic or
ultrasonic device may be an option. These types of level-measurement instruments
really measure the distance from one point in the vessel (usually a reference
point) to the level interface with another fluid. The general operating
principle of both sonic and ultrasonic devices is similar - from ISA and InTech.
Tapping Point Blockage- Automatic Cleaning tool, see the advantages of this advanced technology on the level applications page. This tool has the potential to save big $$ in production downtime, utilities (purge) use and above all has the potential to improve safety.
Thermal Dispersion -The basics, thanks to our sponsors Austral Powerflo Solutions and Magnetrol
10.10
Liquid
Level/Interface Monitoring in Flocculant/Sludge Control - Steven Craig -
Precisely measuring and controlling the mixture of wastewater effluent,
flocculants and sludge is essential to efficient water treatment. The
level/interface instruments that support the process liquid measurements must be
capable of distinguishing between liquids with varying properties in order to
detect the levels where the different liquids interface in the pond or tank -
from Fluid Components International (FCI).
3.11Technical
Handbook from Magnetrol - This comprehensive publication
provides important conversions, chemical properties, equivalents and pipe data -
thanks to ISA.
Level
Technology Comparison - This is a very comprehensive
table- thanks to
our sponsors Austral Powerflo
Solutions and Magnetrol
Taking
the Safe and Easy Approach - A Tune up of your Instrument Practices
- Want to make your process instrumentation installations safer, more reliable,
and easier to use? Then read on for a few insiders tips- thanks
to our sponsors
Austral Powerflo Solutions and Magnetrol
Improving
Differential Pressure Diaphragm Seal
Other Links
Level
Measurement Information Notes- Inx Inc
Level
Calibration Notes - Inx Inc
Level
Overview - a comparison of technologies -(supplied by Able Instruments and
Controls Limited UK)
The
Principles of Level Measurement - Gabor Vass, Princo
Instruments, Inc and sensorsmag.com
Level
Measurement selection Criteria - from omega.com
Water Level
Accuracy and Correcting for Errors
due to Gravitational Acceleration and Liquid Density -
Ronny D. Harris, Ph.D -from In-Situ Inc
Vibrating Switches - The basics - thanks to our sponsors Austral Powerflo Solutions and Magnetrol
Boiler
Drum Level Transmitter Calibration -
Steam Drum Level is both a critical and difficult measurement to
make. Control of the water level in the drum must be
precise. Thanks to Emerson Process Management.
3.11 The
Boiler Drum Level Measurement Guide - Engineers must be ever vigilant to
insure the integrity of the equipment and designs they employ when dealing with
critical process applications. Some processes have been studied quite
thoroughly and necessary control requirements are already well defined. Hundreds
of thousands of boilers have been placed in service and the elements needed for
proper drum level measurement are well understood. Years of experience have gone
into determining satisfactory designs. Unfortunately, a failure to compile and
distribute this information has resulted in many engineers going “back to the
drawing board” for every new project. Isn’t this wealth of experience
available somewhere. New products and methods are being constantly introduced.
But how do these new products combine with existing equipment? Are there
regulations which these new methods must meet? Is this really a new product, or
a research experiment? This excellent 28 page guide is intended to help in the
engineering effort. A sampling of “Tried and True” designs enhanced with the
latest developments in equipment and methodology are presented. Hopefully it
will provide safer operation of the boiler, save time for the design engineer,
and simplify the selection of components that are required to efficiently and
safely monitor and control the boiler drum level - Thanks to The
Clark-Reliance Corporation.
3.11 Boiler
Drum Level Measurement - The primary function of a utility boiler is to
convert water into steam which is used to turn a steam turbine thus, generating
electricity. A steam/water interface exists within the boiler drum. An objective
for safe and efficient boiler operation is to maintain a constant level in the
boiler drum. This can be accomplished by maintaining a balance between the
amounts of steam leaving and water entering the boiler drum. Unfortunately,
boiler drum level control is complicated by changes in electrical load
requirements or variations in the fuel and air supply - from Yokogawa.
3.11Boiler
Drum Level Control - Drum level control is critical to good boiler
operation, as well as safe boiler operation - Jerry Gilman -The drum level must
be controlled to the limits specified by the boiler manufacturer. If the drum
level does not stay within these limits, there may be water carryover. If the
level exceeds the limits, boiler water carryover into the superheater or the
turbine may cause damage resulting in extensive maintenance costs or outages of
either the turbine or the boiler. If the level is low, overheating of the water
wall tubes may cause tube ruptures and serious accidents, resulting in expensive
repairs, downtime, and injury or death to personnel. A rupture or crack most
commonly occurs where the tubes connect to the drum. Damage may be a result of
numerous or repeated low drum level conditions where the water level is below
the tube entry into the drum - from ISA and InTech.
3.11Boiler
Drum Level Measurement and Control - David C. Farthing - Improved
efficiency can have many connotations everything from fuel savings, improved
equipment operation and useful life span, to labour and manpower savings. This
paper will focus on the effects of boiler drum level and feedwater control as a
means of energy savings by thermal/mass balancing the boiler. This paper will
also discuss the effects of steam drum pressure and feedwater temperature on the
overall efficiency of the boiler - from Federal Corporation.
3.11Cascade,
Feed Forward and Boiler Level Control - Allen D. Houtz - One common
application of cascade control combined with feed forward control is in level
control systems for boiler steam drums. The control strategies now used in
modern industrial boiler systems had their beginnings on shipboard steam
propulsion boilers. When boilers operated at low pressure, it was reasonably
inexpensive to make the steam drum large. In a large drum, liquid level moves
relatively slowly in response to disturbances (it has a long time constant).
Therefore, manual or automatic adjustment of the feedwater valve in response to
liquid level variations was an effective control strategy. However as boiler
operating pressures have increased over the years, the cost of building and
installing large steam drums forced the reduction of the drum size for a given
steam production capacity. The consequence of smaller drum size is an attendant
reduction in process time constants, or the speed with which important process
variables can change. Smaller time constants mean upsets must be addressed more
quickly, and this has led to the development of increasingly sophisticated
control strategies - from the controlguru
All
in One Glass - Alternate approach to gage-glass maintenance leads to more
accurate drum level measurement - Dale P. Evely - Southern Company, a producer
of electricity, fiber optics, and wireless communications, developed an
alternate approach to address gage glass maintenance issues as well as
measurement uncertainties associated with water-column-type measurements - from ISA
and InTech
Boiling
Water is easy as One, Two, Three, Four according to David W. Spitzer
There’s more to boiler level control than measuring level and adjusting a
feedwater valve. Improved measurements and inverse response are just a few of
the influences on operating boilers in a reliable manner. Thanks to
ControlGlobal.com
Canal
Flow Measurement Using a Bubbler Water Level Sensor - From the US Government
Hydraulics Lab
3.11 Bubble-Tube
Level System - In a Bubble-Tube Liquid Level System, the level is measured
in a vented vessel by measuring the pressure required to force a gas into the
liquid at a point beneath the surface. This method allows for level measurement
without liquid entering the piping or the instrument. A pressure regulator and
constant-flow regulator combine to establish a consistent flow of clean air or
gas to a bubble pipe immersed a fixed distance in the tank. The flow is
regulated to a very low level, building up pressure in the end of the bubble
pipe. Thereafter, pressure is kept at this value by the escape of air bubbles
through the liquid. Changes in the measured level cause the gas pressure to
build or drop - from ControlAir Inc
More details on Bubbler Tubes can be found in the General Level Theory Section above.
All in One Glass - Alternate approach to gage-glass maintenances leads to more accurate drum level measurements - Dale P. Evely - Southern Company, a producer of electricity, fiber optics, and wireless communications, developed an alternate approach to address gage glass maintenance issues as well as measurement uncertainties associated with water-column-type measurements - from ISA and InTech
The following links are provided with thanks
to our sponsors Emerson
Process Management
Level
Measurement - Transmitters with Seals -Transmitters
with remote seals allow the transmitter
to be removed from direct contact with the
process fluid.
Tank
Level Measurement Capabilities - from Viatran Corporation and dynisco.com
Multivariable
approach to liquid level -Density-compensated
leveling eliminates nearly all error - from InTech
Comprehensive Page on Laser Level - Thanks to our sponsor ZEDFLO.
Radiation Based Level Measurement - from www.omega.com
Principals of Penetrating Pulse Technology- From HiTech-A safe, economical, non-contact, non-invasive, “through the wall” digital technology for accurate level measurement -Leif Lindvall,
Profile
Concepts -These are relatively new very accurate
techniques with particular relevence to the oil and gas industry
Technology
associated with profiler level systems
RF
Level Controls - The basics-thanks to our
sponsors Austral Powerflo Solutions
and Magnetrol
RF
Level Measurement in Lined Vessels with Grounded Shell - from www.omega.com
Dielectric
Constants.htm from Ktek
Are
You Gambling with Your Sightglass? - Selection Strategies for When Failure
Is Not an Option - Andrew Obertanec -Sightglasses are
sometimes called “the weakest link” in a processing system because of the
fragility of the glass. Actually, that’s not necessarily true. A sightglass
need not be a weak link in a processing system because glass, when uniquely
designed, is not necessarily fragile. Thanks to flowcontrolnetwork.com.
Technical
Information and Guidelines for the Specification, Installation and Maintenance
of Sight Glasses in Chemical and Pharmaceutical Processing Plants - This
illustrated "Chemical and Pharmaceutical Sight Glass Application
Handbook" spans the full scope of the subject from descriptions of common
glass formulations to design factors, to a step-by-step checklist for
installation and maintenance. From L.J. Star Inc - You will have to register to
get a copy.
Critical
Standards for Specifying Sight Glasses - Sight glasses are highly engineered
products. Although brands look alike, differences in their specs have tremendous
importance for worker safety, sanitary processes, and maintenance costs. From
L.J. Star Inc.
Mechanically
Prestessed Gas/Steel Sight Windows Resist Pressure and Impact Failure - An
article from Chemical equipment and L.J. Star Inc.
On-line
engineering tutorial on sight glass technology as it applies to chemical
processing and pharmaceutical processing. This free webinar begins with an
overview of the essential aspects of glass, noting the various formulations used
in chemical, food and pharmaceutical process observation equipment.
Concentrating on sight glass selection, installation, and proper maintenance,
the webinar explains how to safely and effectively use sight glasses in process
applications ranging from standard lines to exceptionally demanding applications
with high temperature, high pressure, and sanitary requirements.
Standards
for Tank Gauging - Some of the reference standards used for liquid level or
mass tank gauging worldwide - thanks to Gauging Systems Inc
The
Art of Tank Gauging - This excellent 26 page technical
reference from Enraf gives an excellent overview