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Ultrasonic Flow Metering

Zedflo Australia is a Western Australian company established in 1982. They are proud of the excellent reputation and strong relationships that have developed with industry over the last 20 years and continue to strive to build new relationships. Zedflo supplies a comprehensive range of process control field instrumentation, test & calibration equipment and non-intrusive ultrasonic flow metering, providing solutions to the oil, gas, process, mining and chemical industries. Please support our sponsor Zedflo Australia

Go to Specific Subject: Ultrasonic Flow Meters | Clamp On Ultrasonic Flow Meters | Ultrasonic Flowmeters Recalibration Intervals | Ultrasonic Flowmeters for Custody Transfer | Ultrasonic Flowmeter Diagnostics | Leak Detection and Prevention using Ultrasonic Flowmeters | Ultrasonic Flare Flow Meters | Other Ultrasonic Flowmeter Links |

An Ultrasonic Flowmeter is a device which measures volumetric flow and is non intrusive. It measures the average velocity along the path of an emitted beam of ultrasound. This it does  by averaging the difference in measured transit time between pulses of ultrasound into and against the direction of the flow. There are two physical designs one which is based on a spool installed between flanges in a process line, the second is "clamp on ultrasonic meters" where the ultrasonic transmitter and sensors are installed on the exterior of the pipe. Both Ultrasonic Flow Meters designs are relatively maintenance free, however the clamp on technology has advantages in that they can be retrofitted to existing lines without costly piping modifications. 

The following papers are compliments of  Zedflo Australia

It should be noted that  Siemens Acquired Controlotron in 2006

Ultrasonic Flow Meters

WideBeam™, Cavity-Free™ Ultrasonic Flowmeters Achieve Process and Natural Gas Custody Transfer Accuracy and Performance - WideBeam™, Cavity-Free™ ultrasonic flowmeters have been proven to meet the recently released API standards for liquid custody transfer. This same Cavity- Free technology is now available for gas applications and will meet AGA-9 standards for custody transfer. The two major types of ultrasonic flowmeters available for gas custody transfer measurement are conventional ‘insert’ type meters and Controlotron’s unique WideBeam™, ‘Cavity-Free’ design.

Lightning Protection of Ultrasonic Flow Meters - This document outlines important recommendations for all installations requiring protection from lightning damage-Eli Spalten Senior Applications Engineer, Controlotron.

How Can the Guesswork be Taken Out of Flow Measurement? - Clamp-on Ultrasonic Flow Technology offers several advantages over other flow measurement methods, number one being the utilization of external sensors. They are quickly and easily mounted on the outside of the pipe, making them the perfect choice for retrofit applications and applications where corrosive, toxic or high pressure liquids and gases rule out the option of cutting the pipe. With the use of the WideBeam technology, clamp-on flowmeters  have proven their superiority in both the field and the lab. They offer several benefits:
(a) Measurement of practically any liquid and gas
(b) Performance unaffected by viscosity, flow rate, pipe size, solids and aeration content
(c) High accuracy and repeatability through automatic temperature compensation and zero drift correction
(d)  Installation flexibility on pipe sizes up to DN 9140 (360”)

Reflexor™  Doppler Technology - The Technology - from Controlotron - Doppler flowmeters inject sound into the liquid by a transmit transducer at a known angle and reflects off a moving particle or bubble. The frequency is shifted proportional to velocity of the particle or bubble. The reflected signal is captured by the receive transducer and demodulated by the electronics.

Flowmeters for Water & Wastewater Applications - Unfortunately, there are many preconceptions and misconceptions about the use of ultrasonic flowmeters within a wastewater treatment plant. This Industry Note will provide a clear insight into the proper selection and use of the two types of ultrasonic flowmeters; transit-time and Doppler - From  Controlotron.

The Effect of Temperature Gradients on Ultrasonic Flow Measurement - Claus Nygaard Rasmussen - It has been established that ultrasonic flow meters are influenced by thermal conditions, this technical paper addresses this - from Siemens Flow Instruments.

The Case for Widebeam Ultrasonic Flow Measurement - Matt Bird - The most commonly used method of flow measurement is Transit Time Ultrasonic Flow measurement. Two types available, externally mounted Diametral and insertion type Chordal, have different advantages and disadvantages. This article examines the pros and cons of the Diametral and Chordal Measurement systems, and offers a third solution - from Siemens Flow Instruments.

Theory of Operation: Ultrasonic Doppler Flow Meter - This video details how a Doppler Flow Meter works - from Instruments Direct.

Theory of Operation: Ultrasonic Transit Time Flow Meter - This video details how a Transit Time flow Meter Works - from Instruments Direct.

Clamp On Ultrasonic Flow Meters

The following papers are compliments of  Zedflo Australia

Cost-EfficientOn-Site Check Metering Made Easy - Brian Roughan - When a flowmeter in operation has to be verified, it usually must be uninstalled and transported to a facility for the necessary verification or check-metering. With an on-site verification device, though, this task is made much faster, easier and at a fraction of the cost. When using the right meter, the result can even be as accurate as any off-site verification.

Comparative Advantages of Clamp-on Transit-time Ultrasonic Flowmeters over Conventional Intrusive Flowmeters- Recent developments have enabled today’s clamp-on transit-time ultrasonic flowmeter technology to reach a level of applicability, functionality, economy and performance which establishes this instrument as the prime candidate to replace most, if not all, the conventional intrusive flowmeters in most of their niche applications. This paper describes the advances that have taken place and how users of conventional intrusive flowmeters may evaluate for themselves the advantages available to them by use of the clamp-on transit-time ultrasonic flowmeter in place of any of their prior intrusive flowmeter types - Joseph Baumoel, President, Controlotron.

The Ultimate Flowmeter, High Precision - Low Cost -Joe Baumoel, President,Controlotron Corporation -  High precision and low cost are usually incompatible concepts. Providing precision is usually the thing that leads to high cost in a flowmeter. However, start with a high cost-high precision clamp-on ultrasonic flowmeter and take out the costly functions and features that are not needed for most applications and you have a non-intrusive high precision-low cost flow meter! 

Clamp on Ultrasonic Flowmeters - Your Questions Answered - Thanks to our Sponsor Zedflo Australia

Suggested Permanent Multifunction Clamp-On Dual Channel/PathTransit-Time Ultrasonic Flowmeter Specification - A useful typical specification from Controlotron

Clamp-On Ultrasonic Meter Applications - William E. Frasier - I have applied the Siemens clamp-on meter in many configurations in the field and will describe purposes and findings on the way to precise meter certainty. The clamp-on system provides an effective new tool for insight into the flowing regime within a pipe - from the American School of Gas Measurement Technology.

The following articles are from Siemens;

Applications in Liquid Measurement Using Clamp-On Ultrasonic Technology - Sid Douglass - Ultrasonic meters are typically used to measure flow and clamp-on ultrasonic meters are no exception. One will find these meters installed in most aspects of the petroleum industry. This white paper details some of these applications - from CRT services.

Ultrasonic Clamp On Flow Meter Application Reports – A series of reports on Clamp On Ultrasonic Flow Meter applications across a wide range of industries – from TOKYO KEIKI INC

Siemens SITRANS FUS1010 Clamp-On Flowmeter Installation Guideline - Learn how to get started with the FUS1010 clamp-on ultrasonic flowmeter, including identifying and selecting sensors, choosing a mounting location and programming the meter. SITRANS FUS1010 is the most versatile clamp-on meter on the market today, with maintenance-free external sensors that eliminate the need to cut the pipe or stop the flow.

Validating SITRANS F US Clamp-on Flowmeter Performance - Learn how to use several simple diagnostic tools on any SITRANS F US clamp-on ultrasonic flowmeter to ensure that the flowmeter is operating properly and the readings are as accurate as possible. The SITRANS F US flowmeter line from Siemens provides precise measurement of liquids and gases and features maintenance-free external sensors that eliminate the need to cut the pipe or stop the flow.

Other Useful Clamp on Ultrasonic Flow Meter Links

Fundamental Principles of Clamp on Ultrasonic Flow Meters - Overview of selection, Installation, Operation and maintenance of clamp-on meters - William E. Frasier Jr -  This paper is aimed at ultrasonic natural gas meters that use transit time across the gas pipe as the measurement variable. Custody transfer meters using sensors wetted with gas are the more familiar meter format. Clamp-on meters are quite similar - from the American School of Gas Measurement Technology.

Clamp-on Ultrasonic Flowmeter Improvements - Ultrasonic flow measurement technology offers a low-cost method to measure flow. The advantage of clamp-on ultrasonic flow sensors is installation without stopping a process to put a hole in a pipe to insert a conventional sensor. From InTech and the ISA. 

A Clamp-On Ultrasonic Flowmeter for Gases - Michael J. Scelzo - Despite the industrial success of clamp-on ultrasonic flowmeters for liquid measurement, it has long been accepted as if it were a fundamental limit imposed by nature, that this technology could not be used to measure the flow of gases in metal pipes. The incorrect conclusion, that clamp-on gas flow metering is impossible, developed because the acoustic impedance of gases, even at pressure, is much less than the acoustic impedance of metals - from GE Measurement & Control Systems.

Full Steam Ahead - Clamp-on Flow Measurement no Longer just for Liquids - Daryl Belock - When plant engineers look for a non-intrusive flow measurement solution, clamp-on ultrasonic flowmeters are typically the first technology considered. Users traditionally have considered clamp-on technology only for liquid applications. For years flowmeter manufacturers have been asked,“Do you have a clamp-on solution for steam?” Until recently the answer has been no, but new technology now makes clamp-on steam flow measurement a reality for many common types of steam flows - from GE Measurement & Control Systems.
Water System Standardises on Clamp-On Ultrasonic Flowmeters - Daryl Belock & Phil McDonald - from GE Measurement & Control Systems.

Strength in Numbers - Matching Lamb Wave Sensors to the Resonant Frequency of a Pipe Wall - James Doorhy - Clamp-on ultrasonic flowmeter technology offers several major advantages over other methods of flow measurement when it comes to accounting for what, and how much, is flowing through a pipe. These benefits are derived primarily from one very important feature of clamp-on ultrasonic meters — i.e., their external sensors. Unlike traditional insert sensors, external sensors do not require pipes to be cut or operations to be halted in order to complete the installation process. Instead, the sensors are mounted on the exterior of the pipe and measure flow by transmitting acoustic signals into the pipe wall before entering the fluid - from Siemens.

Ultrasonic Flowmeters Recalibration Intervals

The following papers are from the excellent CEESI Flow Measurement Technical Library - A superb resource!

Flow Calibrating Ultrasonic Gas Meters - Joel Clancy - The primary method for custody transfer measurement has traditionally been orifice metering. While this method has been a good form of measurement, technology has driven the demand for a new, more effective form of fiscal measurement. Ultrasonic flowmeters have gained popularity in recent years and have become the standard for large volume custody transfer applications for a variety of reasons. Most users require flow calibrations to improve meter performance and overall measurement uncertainty. The latest revision of AGA Report No. 9, Measurement of Gas by Multipath Ultrasonic Meters, Second Addition [Ref 1], now requires flow calibration for ultrasonic flow meters when being used for custody transfer applications. What considerations then, should be taken when choosing to flow calibrate an ultrasonic flowmeter? What are the benefits to the user? What should a user expect from a flow calibration? What kind of performance should the customer expect or accept from an ultrasonic meter? What are the diagnostic capabilities inherent in an ultrasonic meter? These areas, as well as others will be explored and considered - from CRT Services.

Ultrasonic Flowmeters for Custody Transfer

The following papers are from the American School of Gas Measurement Technology

Ultrasonic Flowmeter Diagnostics

Guidance Note - Application of Ultrasonic Flow Meter Diagnostics - Improvements in digital signal processing techniques have enabled large amounts of data to be processed and stored in real time. Manufacturers of modern flow meter devices such as ultrasonic meters (USMs) have taken advantage of these improvements and are now using diagnostic parameters to perform a ‘health-check’ of the meter when in operation. This can help the diagnosis of potential problems with the measured fluid or the measurement system - from NEL.

Leak Detection and Prevention using Ultrasonic Flowmeters

Clamp-on Leak Detection Solution for Enhanced Pipeline Management - When a pipeline leak occurs, it causes a sudden decrease in pressure at the leak origin. This pressure transient radiates both upstream and downstream from the line breach and decreases the density of the liquid, which results in a sudden drop in the liquid‘s sonic propagation velocity (Vs). The change in Vs is detected at each site station and time stamped with the arrival of the pressure wave‘s leading edge. As a result, the highly accurate FUS-LDS can locate a leak event within ±150 meters - from Siemens.

Leak Detection & Pipeline Management Solutions - SCADA based leak detection systems depend on data from existing Turbine or PD Flowmeters, and pressure and temperature instruments originally installed by others. These instruments were not originally specified to provide the extraordinarily high accuracy and calibration stability needed for leak detection. Therefore, system performance cannot be assured by the SCADA system supplier. No single party can be held responsible for SCADA based leak detection system performance. All elements of the LD system are provided by Controlotron to assure the specified leak detection accuracy. Controlotron takes responsibility for system installation, start-up, optimization and maintenance. In addition, the LD system’s compensated volume balance principle provides continuous leak detection, not the “one shot” leak detection provided by pressure based SCADA systems.

Leak Detection and Prevention - Joseph Baumoel, Controlotron, USA, Provides an overview of the ongoing problem of pipeline spills and evaluates the technologies available for the identification and control of pipeline leaks.

Technical Review of Leak Detection Technologies - Volume I - Crude Oil Transmission Pipelines - Analysis of recent data from the U.S. Department of Transportation Office of Pipeline Safety (DOT-OPS) indicates that, despite stricter regulations and enforcement, the rate at which pipeline accidents occurs has not significantly changed over the last two decades (Hovey and Farmer, 1999). The statistics suggest that short pipelines will have at least one reportable accident during a 20-year lifetime and longer pipelines (800 or more miles of line pipe) can expect a reportable incident every year. Research indicates that the best opportunities to mitigate pipeline accidents and subsequent leaks are through prevention measures such as aggressive controller training and strict enforcement of safety and maintenance programs (Hovey and Farmer, 1999; Borener and Patterson, 1995). The next most productive enhancement comes from implementing better pipeline monitoring and leak detection equipment and practices. Early detection of a leak and, if possible, identification of the location using the best available technology allows time for safe shutdown and rapid dispatch of assessment and cleanup crews. An effective and appropriately implemented leak detection program can easily pay for itself through reduced spill volume and an increase in public confidence - from Alaska Department of Environmental Conservation.

Ultrasonic Flare Flow Meters

How can you Measure the Flare Gas in Your Storage Tank? - Lonnie Barker -  A way to use an ultrasonic flow clamp-on unit that would help accurately and reliably measure the gas in this challenging application - from Siemens.

How do you Measure Flare Gas Effectively with Clamp-On Ultrasonic Flow Meters? - Martin Dingman - If you flare-off gas rather than use a vapor recovery unit (VRU), or even flare-off the exposed gas after using the VRU, then you may have already experienced your share of challenges – particularly when it comes to measuring the gas you’re flaring. Challenges can arise from a number of external agents. In particular, inaccurate and unreliable measurements of flare gas applications running under low (and extremely low) pressures in steel pipes. Whether you are venting into the atmosphere or into a VRU, the biggest challenge in measuring low pressure flare gas in steel pipes is the conflict in their acoustic impedances that isn’t suitable for clamp-on ultrasonic flow meter measurement. This blog discusses a solution - from Siemens.

How much Do You Flare? - How to Measure Flare Flow Rates Reliably and Accurately - Ultrasonic Flowmeters help compliance with Environmental Emission Requirements, reduce Leaks and Understand their Process Losses -  from GE Measurement & Control Systems.

Other Ultrasonic Flowmeter Links

Ultrasonic Flowmeters -By David W. Spitzer -  Parts 1 to 4  - The flowmeters to be discussed use ultrasonic energy or correlation as their primary flow measurement technique. Therefore, a common class of "ultrasonic flowmeters" comprised of an open channel flowmeter (such as a flume or weir) that incorporates an ultrasonic level measurement is specifically excluded from this discussion. Ultrasonic flowmeters use sensors to generate ultrasonic waves and direct them into the flowing stream. Information from the remnants of these sound waves is used to determine the flow of fluid passing through the flowmeter. Ultrasonic flowmeters have no moving parts.

Ultrasonic Flowmeters Move Into the Mainstream - Walt Boyes, Editor in Chief -Thanks to 

Ultrasonic Flow Measurement - Technology -From

Are Ultrasonic Flowmeters Right for You?- From Automation World

Ultrasonic Doppler Flowmeters- Flow reference from Omega

Effluent Flow with Suspended Solids -Facing Rising Treatment Costs, Paper Mill Reconsiders Flowmeter Installation - This article describes some solutions to this issue - David W. Spitzer, P.E.- Thanks to flowcontrolnetwork,com

University Chilled Water Plant Plays it Cool with Ultrasonic Flowmeters - An application article - From InTech and the ISA

Total Life Cycle Investment: Changing how we think about Well Head Gas Flow Meters-Tim Hayes - Operations Engineer, Spring Gully - In a time when large capital ventures are realising the need to consider total life cycle operational costs, reviewing lower maintenance flow meter technology may see a decrease in the expected operational expenditure on large Coal Seam Gas (CSG) projects - thanks to the Origin Energy Talent Search Team.

 The following excellent Ultrasonic Flowmeter Papers are from Cameron-Caldon

Proving Liquid Ultrasonic Meters - Christopher B. Laird - Proving is the process that determines the accuracy of a meter. A prover is a device with detector switches that define a precise, known volume. The prover is connected in series with the meter being proved so that as flow passes through the meter, the same flow, and only that flow must pass through the prover. The flow moves the displacer in the prover until it touches the first detector switch, the pulses coming from the meter start being counted by a prover counter. When the displacer touches the second detector switch, the pulses from the meter stop being counted. In this way, the exact number of pulses generated by the meter for an exact amount of flow is determined and the actual volume registration of the meter can be compared to the known volume of the prover. The ratio of the volume of the prover to the volume registered by the meter is called the Meter Factor. The proving process involves taking the average of several tests (comparisons) of the above mentioned ratio and checking the consistency of the tests. For example, if 5 tests or proving runs are made, the ratios must agree within 0.05%. If they do, then statistically, the uncertainty of the average Meter Factor will be within 0.027% and will meet industry requirements - from CRT Services

The following papers are from the American School of Gas Measurement Technology;

The following Technical Papers are from Emerson Process Management;