Measurement Library

FLOMEKO Publications (2003)

Modelling Wet-Gas Annular-Dispersed Flow Through A Venturi
Author(s): m. Van Wervena, G. Oomsb, B.J. Azzopardic, H.R.E. Van Maanena
Abstract/Introduction:
A theoretical model for gas-liquid annular-dispersed flow through a Venturi meter is reported. It is based on an earlier model developed for Venturi scrubbers. Changes implemented are based on new research and on the different physics between the two cases. The predictions of the model have been tested using information from recent experiments on Venturi meters employed for measuring wet gas flows with liquid volume fraction up to 10%. The model gives good predictions.
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Document ID: D57D29EB

Z/Z-METER, On-Line Measurement Of Compressibility-Ratios For Reference Values Of Volume At Operational Conditions
Author(s): A.J.M. Herwijn
Abstract/Introduction:
One of the methods to realize reference values for Volume of e.g. Natural Gas at increased pressures is via a calibration under a pressure difference (i.e. with expansion). In such a process, applied since the sixties in the Netherlands 1, 2, the un-known meter or Meter-under-Test (MuT) is compared through expansion with the known meter or Reference Meter (RM) at low-pressure. In a normal calibration-process the difference in pressure between the two compared meters is relative small and the resulting difference between the compressibility at the Reference Meter ZRM and the compressibility at the Meter-under-Test ZMuT has hardly any effect on the ratio ZRM/ZMuT and can be neglected (the ratio is thus considered to have a value of 1). However, in a calibration under expansion a comparison is made of a gas-flow under significant differential pressure-conditions and one of the most important contributions of uncertainty stems from the real gas constant Z. So, the ratio ZRM/ZMuT is of importance, rather than the absolute values of the compressibility factor. The Z/Z-meter is one of the current technical developments at NMi VSL-Flow 3, 4. The uncertainty contribution in the conventional method of calculation, described e.g. in M-GERG 5, 6 of 1991, is rather high (0,1% for the compressibility factor) and the resulting uncertainty of the ZRM/ZMuT ratio is 0,14%.
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Document ID: C56F6144

Nmi Trasys, The Ultimate Carrier & Multiplier For The Unit Of Volume For High-Pressure Natural Gas
Author(s): M.P. Van Der Beek,J. Landheer
Abstract/Introduction:
The paper describes the newly developed NMi TraSys - NMi Traceability System. This travelling carrier & multiplier of traceability has been realized to embody a significant part of the Dutch National traceability-chain for high-pressure gas-flow measurements. The number of contributions of uncertainty as well as their values, due to copy-losses and installation-effects during the traditional transfer of traceability from one facility to another, are decreased. First results are presented about observed repeatability and reproducibility, uncertainties and consistency checks. The device will include in time, reference values of three different independently realized primary standards (viz. DDD - Dynamic Displacement Device, GOPP - Gas-Oil Piston-Prover and NMi TraSys itself). With internal harmonization processes at NMi VSL with input reference values from the three other primary standards, viz. DDD-conventional, DDD-extended pressure level and GOPP, the aim of 0,1% uncertainty at 4.000 m3/h and p 60 bar is within reach. This will improve the uncertainty as well as the stability of the Dutch National reference values considerably. NMi TraSys will be used as a set of Travelling Reference Meters, creating an efficient availability of stable and validated Harmonized Reference Values for high-pressure gas-flow.
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Document ID: 151249AF

Quadratic Weighing, Applied In Harmonization, A Tool To Compare The Performance Of Test-Facilities
Author(s): R. Van Den Brink, M.P. Van Der Beek, I.J. Landheer
Abstract/Introduction:
Measurement-data of laboratories participating in comparisons are often treated equivalently with respect to operational conditions and statistical impact. When analysing the comparison, this may distort some conclusions because no attention is paid to deviations caused by differences in operational conditions (e.g. pressure). A better way to perform a comparison is to transpose the sets of flow-rate data to Reynolds numbers, to make it easier to see whether or not the points are in the same Reynolds-region and thus allow for a valid comparison. Next, not all participating laboratories contribute equally to establish a Mean (Average) Value, because the laboratories with a low uncertainty must have a greater impact on the final result than laboratories of a lesser quality. So the data -sets must be weighed and to do so, weighing-factors are needed. Finally, a common way to analyse the comparison-results is by using Youden-plots. This paper shows the flow-rate to Reynolds-transformation to compare test-data, and demonstrates which weighing-factors must be used to get the Best Known Mean Value with the smallest uncertainty. In the end, this method is also applied in Youden-plots.
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Document ID: CB52C8F3

Gas-Oil Piston-Prover, A New Concept To Realize Reference Values For High-Pressure Gas-Volume In The Netherlands
Author(s): M.P. Van Der Beek, R. Van Den Brink, I.J. Landheer
Abstract/Introduction:
The paper describes the recently developed GOPP - Gas Oil Piston-Prover. This primary standard for high-pressure gas-volume is created to realize units of volume at various pressures for the Dutch National traceability-chain of high-pressure gas-flow measurements. The paper presents the design, working principle, simulation calculations and first results to realize a calibrated rotary-piston gas-meter. Furthermore, the actual physical process is compared to simulation calculations, and temperature characteristics are discussed. With internal harmonization processes at NMi VSL with input reference values from the three other primary standards, viz. DDD-conventional, DDD-extended pressure level and NMi TraSys, the aim of 0,1% uncertainty at 4.000 m3/h and p 60 bar is within reach. This will improve the uncertainty as well as the stability of the Dutch National reference values considerably.
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Document ID: E7696C68

Periodical Control And Dynamic Traceability Test Of An SNPS1 To The National Standard Of Gas Flowmeters Calibration
Author(s): Alex S. Kun, Balazs Rekasi
Abstract/Introduction:
The tested Sonic Nozzle Prove ring System (SNPS) stepped into service at the Gas Works of Budapest almost five years ago. To keep its parameters in a dedicated and good condition a continuous checking process is carried out. During this checking process those tested were the SNPS main accuracy and repeatability, as well as the individual sonic nozzles (SN). Keywords: Sonic Nozzle Provering System (SNPS), sonic nozzles (SN). Dynamic traceability, interlaboratory comparison test
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Document ID: 902F0029

The Mikes Measuring System For Gas Mass Flow
Author(s): Sampo Sillanpaa, Martti Heinonen
Abstract/Introduction:
Due to the increasing need for traceable gas flow measurements in Finland, the development of a national measurement standard for gas mass flow was initiated at the Centre for Metrology and Accreditation (MIKES) in 2002. A primary calibration system based on dynamic weighing was constructed to provide traceability directly to the national mass and time standards. The MIKES gas flow measuring system includes also a commercial calibrator based on laminar flow elements. It is used as a working standard when calibrating mass flow meters for customers. The calibration range encompasses 0,4 mg/s to 625 mg/s. The relative standard uncertainty of the gravimetric system is between 0,2 % and 0,4 %.
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Document ID: B43414B8

Speed Of Sound Measurements In Gas-Mixtures At Varying Composition Using An Ultrasonic Gas Flow Meter With Silicon Based Transducers
Author(s): Torbjrn Lfqvist, Kestutis Sokas
Abstract/Introduction:
This paper concerns speed of sound measurements performed in three different gas mixtures at constant temperature and pressure while the concentration of the gases was varied. The performed experiments used an ultra sonic, sing-around, gas flow meter equipped with silicon based transducers. The center frequency of the transducers was 800 kHz. Speed of sound was measured in mono-, di- and triatomic gases: argon (Ar), oxygen (O2) and carbon dioxide (CO2), in either air or nitrogen (N2) as a background gas. The gas under investigation was mixed with the background gas in a test chamber and the concentration of the gas under examination was varied between 0% and 100%. A gas chromatograph was used in order to accurately determine the composition of the gas mixture. The experiments show that measured speed of sound, as a function of gas composition, agrees with the speed of sound obtained from theory. The achieved data also show that the speed of sound measurements was performed with low standard deviation. Thus, one can conclude that this type of ultrasonic gas flow meter is well suited in determining gas concentration in a binary gas mixture as well as flow velocity. The technique could be of value in both industrial and medical applications.
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Document ID: CBF6052A

Title: The Design And Application Of Clamp-On Ultrasonic Flowmeters For Custody Transfer And Check Metering Gas Applications.
Author(s): Douglas Baumoel
Abstract/Introduction:
Fluid Type: Gas Topic: E: Issues dedicated to Specific Metering Recent advances in externally mounted sensor design and related electronics have enabled gas meters using clamp-on, non-intrusive, ultrasonic transducers to provide performance equal to or better than meters using conventional insert transducer technology. It is acknowledged that this claim will be met with skepticism however, the following pages provide evidence of this performance capability. This paper also presents the technical challenges to this design, and how they were overcome. We will review the applicability, benefits, and limitations of the various configurations of this technology.
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Document ID: DF1E2B9D

Investigation Of Flow Conditioning In Pipes
Author(s): Gabriel Moniz Pereira, Bodo Mickan, Rainer Kramer, Dietrich Dopheide
Abstract/Introduction:
It is a well-known and recognised fact that the behaviour of flow rate and volume measuring devices can be affected very strongly by the flow conditions prevailing in their inlet pipe section. Disturbed velocity profiles caused by pipe configurations such as bends, headers, pressure regulators and convergent or divergent pipe sections in front of a flow meter can lead to deviations of the meter reading by up to several percents. Thus, flow conditioning normally means the generation of fully developed flows in the inlet of meters to avoid installation effects. Since this is in practice not always possible, it is necessary to investigate the influence of flow perturbations to the behaviour of flow meters. Such investigations are normally part of pattern approval in legal metrology. Hence, in case of pattern approval flow conditioning means the generation of disturbed flows with a definite and reproducible level of perturbation. The International Organisation of Legal Metrology OIML defined therefore standard pipe configurations (e.g. in OIML Recommendation R 32 1) to perform perturbations test within pattern approvals.
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Document ID: C54A63F7

Time Dependent Performance Of Turbine Gas Meters
Author(s): A. Saglam, P.M.A. Van Der Kam, G.J. Van Essen, D.H. Hebels
Abstract/Introduction:
Gastransport Services in the Netherlands, uses turbine gas meters to measure the gas flow to local gas distribution companies, large industrial customers and power plants GTS operates approximately 1100 city gate stations, at a delivery pressure of usually 8 bar. In the Netherlands, the procedures for determining the operational performance of the turbine meters are agreed upon between Gastransport Services and its customers. As a result of this agreement, Gastransport Services inspects the total population of turbine meters by means of the well-known variables-acceptance-sampling. Each year, 60 turbine meters are selected randomly from the total population. Subsequently, the selected turbine meters are calibrated traceable to international standards by Netherlands Measurment Institute (NMi). The information from these recalibrations is used to study the stability of the turbine meters. Because, through the years a lot of information has been gathered on the turbine meters performance, the presence of statistically significant relationships (correlation) between the performance in time of the meters on the one hand and properties like the construction year, the pressure class, the size, the maximum allowable flow rate and/or the recalibration period of the meter on the other hand, can be investigated. In this presentation, analysis -of-variance and the quadrant-correlation-test are used to test for the presence of such correlations. The aforementioned five properties were analysed for the presence of correlation at two different calibration pressures and with different definitions of drift to express the performance in time of gas turbine meters. For a specific calibration pressure and a specific type of drift, the performance in time dependents on the recalibration period and the size of the turbine meter. Furthermore, the correlation analysis, showed that a turbine gas meter seems to reach a steady state in time, expressed in terms of shift of the weighted mean error. (*) To whom correspondence about this paper should be addressed. KEYWORDS: Time dependent performance, turbine meters, drift, shift of the weighted mean error, analysis -of-variance, quadrant-correlation-test, least significant difference, correlation analysis
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Document ID: D2842841

Phase Modulation Of The Ultrasonic Wave In Von Karman Street
Author(s): Mustafa Music
Abstract/Introduction:
It is known that under certain conditions (in certain Reynolds number region) we get double row of staggered vortices in fluid flow behind the bluff body. Frequency of generated vortices is directly proportional to the average velocity of fluid and that dependence is linear. Flowmeters based on this phenomenon are known as vortex flowmeters. Origination of vortices causes changes some other parameters such as: pressure, perpendicular forces on fluid flow, etc. Frequency of vortices can be detected by detecting changes of these parameters. Great majority of the vortex flow meters are functioning using this principle. Mathematical model of the phase modulation of ultrasonic wave that is transmitted normally on the fluid flow behind the bluff body in the region of stable flow will be given in this paper. Phase modulation is directly caused by appearance of vortices in the fluid flow. We have developed the prototype of ultrasonic vortex flow meter (PVMP 100) DN 100 based on phase ultrasonic modulation, for liquid flow measurement fig.1. Experimental results of testing this prototype vortex meter will be presented in this paper.
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Document ID: AC51C878

Theory Of A Coriolis Mass Flowmeter Insertion Probe
Author(s): Lynn A Hendry, John Hemp
Abstract/Introduction:
A novel Coriolis mass flowmeter insertion probe concept is described suitable for the measurement of the mass flow of liquids flowing in pipes. It is generally similar to that of the turbine meter insertion probe for volume flow measurement except that the turbine is replaced by a small vibrating aerofoil of elliptical cross-section. The weight vector theory of Coriolis mass flowmeters is applied to predict the approximate sensitivity of the probe. The sensitivity so predicted can be comparable to that of commercial (vibrating tube) Coriolis mass flowmeters so that the signal processing techniques developed for these could be directly used in conjunction with the proposed insertion meter. The dependence of sensitivity on Reynolds number and on liquid density is discussed and a way of removing dependence on liquid density is described.
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Document ID: DE5581A1

New Test Facility For Large Water Flowrates Up To 1000 m3/h In A Temperature Range Between 3 C And 90 C At Ptb - Berlin
Author(s): Thomas Lederer,, Nicolaus Mathies, Jrgen Rose, Dieter Stuck
Abstract/Introduction:
PTBs Thermal Energy Measurement Section built up a new gravimetric test facility, serving as the national primary standard for volume flowrates of water from 3 m3/h to 1000 m3/h and temperatures between 3 C and 90 C. The maximum Reynolds number achieves a value of 5.5106 .The test facility can be operated in four different modes to generate the water flow and comprises two independent weighing procedures, to obtain highly-valuable measurement results with an expanded combined uncertainty of 0.04%. This paper describes the test facility with particular consideration of the technical methods to achieve this high accuracy level.
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Document ID: F60FCD2E

A New Sightly Bent Single Tube Coriolis Mass Flowmeter For Corrosive Fluids
Author(s): Martin Anklin, Alfred Wenger
Abstract/Introduction:
Coriolis mass flowmeters (CMF) have proven to measure mass flow very accurately to better than 0.10% for water. The high accuracy and rangeability of CMF is one reason for its fast growth and acceptance in industry. The commercially available CMF show a broad variety of designs, such as single tube, dual tubes, bent tubes or straight tubes. Since CMF are available with different tube materials like stainless steel, Hastelloy and titanium, they can be used for all kinds of liquids or gases. However, there are only few designs, which can withstand highly corrosive fluids. Such sensors are made out of tantalum, zirconium or contain lined tubes. On one hand, tantalum shows a very good performance under acidic conditions, on the other hand is has the disadvantage of its high price, which leads to very expensive sensors. Zirconium is much cheaper and has nearly the same corrosive performance for many acidic and alkaline fluids like, hydrochloride acids, acetic acid, hydrogen peroxide, urea and others. The cheaper price of zirconium versus tantalum also allows to develop larger size sensors up to DN50 (2) with reasonable costs for the customer. Therefore, the design of the new CMF is made the way, that all wetted parts consist of zirconium R60702. The new single tube CMF is called Promass H and its design is schematically shown in figure 1.
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Document ID: AC7353EB

Coriolis Mass Flow Meter With Direct Viscosity Measurement
Author(s): Michael Fuchs, Wolfgang Drahm, Christian Matt, Alfred Wenger
Abstract/Introduction:
Four process variables from one meter Coriolis mass flowmeters are widely used in industrial flow measurement. Mass flow is measured directly with very high accuracy ( 0.1% for liquids). These instruments are real multivariable meters, because all meters include direct temperature and density measurements as well. From theses primary measured parameters, , even further variables can be derived e.g. concentration measurement based on density. The trend in industry shows an increased need for such multivariable instruments, which is due to increased global competition and, thus, requires better process efficiency and stricter quality control. Improving quality and process enables manufacturer to save costs by reducing production time and wasted material. Now, additionally to mass flow, density and temperature measurements, also direct viscosity measurements are successfully integrated into Promass 83 I, which is a single tube Coriolis mass flowmeter with a straight tube. Viscosity is a crucial process variable indicating important fluid properties like consistency, pourability and concentration, which can define the quality of a product. Viscosity can also be an important indicator for problems within a process and, thus, allows the manufacturers to adjust process parameters immediately to prevent a whole batch to be wasted. With these in-line measurements, no time is lost for separate laboratory viscosity measurement. This paper explains the working principle of the new additional viscosity measurement and demonstrates its opportunities.
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Document ID: EC3EFB40

Two-Phase Flow Measurement Based On The Analysis Of The Sensor Signal From A Conventional Vortex Flowmeter
Author(s): m. Pusayatanont, P.J Unsworth, E.H Higham
Abstract/Introduction:
This paper presents a new technique for measuring the volumetric flow rates of each phase in a twophase gas-in-liquid flow regime, by analysis of the sensor signal from a conventional vortex flowmeter. The vortex flowmeter has become established throughout the process industry for the measurement of both liquid and gas flows, principally because of its wide rangeability, coupled with a nearly linear relationship between the vortex shedding frequency and volumetric flow rate, plus the fact that it has no moving parts which are liable to deteriorate in service. In recent years, the measurement of multiphase flow has become increasingly important in the management of oil wells, and there are also many instances in the process industries where it would be helpful to have on-line measurements of this type. It has therefore been the subject of extensive research because virtually all available flowmeters are suitable for measuring only single phase flows, and when a second phase is introduced their performance is seriously impaired and in some instances they may cease to function.
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Document ID: FB4E450E

Analysis Of The Sensor Signal From A Turbine Flowmeter To Recover Information Regarding The Flow Regimes
Author(s): M.Pusayatanont, E.H Higham, P.J Unsworth
Abstract/Introduction:
The paper discusses the identification of turbine flowmeter fault conditions by recovering additional information from the unconditioned sensor signal. Turbine flowmeters are characterised by their high accuracy, excellent repeatability, good linearity and wide operating range. However, they are very sensitive to the change of flow regime and system conditions, which can degrade the flowmeter performance and, in particular, the accuracy of measurement. Four general fault conditions - erosion or damaged of the rotor blades, swirling flow, pulsating flow and two-phase flow - have been simulated and studied. The laboratory experiments provide very strong evidence that there is much useful information embedded in the sensor signal that can be recovered and used to identify the operational status of the flowmeter. The experimental results show that additional information regarding attributes and features of flowmeter itself, as well as its operational status and the condition of the flow regime in which it is operating, can be recovered by analysis of the unconditioned sensor signal.
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Document ID: EAA2DE82

Analysis Of The Sensor Signal From A Vortex Flowmeter Tot Recover Information Regarding The Flow Regimes
Author(s): m. Pusayatanont, E.H Higham, P.J Unsworth.
Abstract/Introduction:
The paper discusses the effects of non-standard flow regimes on the performance of vortex flowmeters and the methods of analysing the vortex sensor signal to detect the presence of these spurious conditions in the flow, and swirling flow in particular. This study shows that the amplitude and frequency fluctuations embedded in vortex sensor signals carry much useful information about system conditions and fluid flow regimes which can seriously impair the accuracy of measurement. The necessary signal information can be recovered by analysing the unconditioned raw vortex sensor signal i.e. utilizing data regarding fluctuations in signal amplitude and periodicity.
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Document ID: EB6F4408

Modal Analysis Of Coriolis Mass Flowmeter
Author(s): Tong Meng, Ren Ping, Chen Ming
Abstract/Introduction:
Coriolis Mass Flowmeter (CMF) is true mass flowmeter, by measuring the Coriolis effect of a vibrating flow pipe. Dynamitic Analysis of CMF plays an important role in its design and application. Finite element modal analysis of CMF Assembly and flow pipe individually is presented in the paper. CAD Model of CMF Assembly is built in AutoCAD, and then imported into FEM software Msc. Marc, and rotated to generate solid FEM model. Lanczos method is adopted in the calculation. Effects of type of the flow pipes support are investigated. Its presented the FEM calculations are agreed with the theory analysis of Euler beam.
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Document ID: A25F77AF

Performance Improvement Of Liquid Flow Calibrators By Applying Special Measurement And Control Strategies
Author(s): Rainer Engel, Hans-Joachim Baade, Droege, Andreas Rubel
Abstract/Introduction:
PTB?s new Hydrodynamic Test Field, which represents a high-accuracy water flow calibration facility, will serve as the national primary standard for flow measurands: volumetric and mass flow rate, respectively, and total flow measurement, i.e. the quantity of fluid (volume or mass) passing a flowmeter. Owing to this application aspect, the main design goal was to realize a total expanded measurement uncertainty as low as 0,02 % for total volumetric flow-rate measurement. To meet this decisive requirement, low-uncertainty components were combined with state-of-the-art measurement and control strategies.
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Document ID: 03E9F577

The Impact Of Flow Dynamics In The Design Of Flow Meters And Metering Stations
Author(s): E. Van Bokhorst, M.C.A.M. Peters, F.M. Braal
Abstract/Introduction:
1. Introduction Commercially available flowmeters are provided with a calibration certificate, based on stationary flow conditions and do not include the impact of installation effects like swirl, a-symmetry, and piping and flow dynamics. Flow pulsations, valve noise and mechanical pipe vibrations can have a considerable impact on flowmeter accuracy in gas as well as in liquid flows.
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Document ID: 023BB15B

Calibration Of 24 Ton Weighing Scale By Coriolis Mass Master Meter Uncertainty Calculation In Load And In Load Difference
Author(s): Aart Pruysen
Abstract/Introduction:
At the MicroMotion Flowfacilities ( division of Emerson Process Management) in Veenendaal - the Netherlands, the Coriolis MicroMotion meters are gravimetric calibrated for the European users via the standing start and stop method. These flowfacilities have a stand uncertainty (Calibration and Measurement Capability CMC) of 0.03%
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Document ID: A97EC109

Detection Of Improper Mounting From The Sensor Signal Of Vortex Owmeters
Author(s): A. G. Rossberg, P. Riegler, F. Buhl, J. Herwig, J. Timmer
Abstract/Introduction:
In vortex owmeters, the frequency of vortex formation at a blu body inserted into the ow is used to determine the ow velocity. The frequency is determined using a sensor that measures the time-dependent distortions of the down-stream ow eld. But the (univariate) sensor signal contains more information than just the vortex frequency. We use this inherent extra information to verify if the pipe ow has the form expected for the correct mounting of the owmeter, and thus, if the ow measurement has the expected high accuracy. In designing the method, special care was taken to leave it robust with respect to uncertainties in the material properties of the uid. In order to achieve this goal, the method makes use of the scaling properties of the Navier-Stokes equation. We present the theoretical background of the proposed diagnostic functionality and verify it on measurement data. In the experiments, irregularities that lead to more than 0.5% error in the output of the owmeter can clearly be detected.
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Document ID: D64B3CBC

Influence Of Shape Deviations On The Measurement Precision Of Vortex Flow Meters
Author(s): Ernst Von Lavante
Abstract/Introduction:
Ernst von Lavante, Institute of Turbomachinery, University of Essen, Essen, Germany Burger Nath, ABB Automation Products GmbH, Goettingen , Germany
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Document ID: 590843E3

Correction For K Factor Of Gas Turbine Flow Meter
Author(s): Xue Chunling, Sun Yanzuo
Abstract/Introduction:
According to the International Standard ISO 9951 all gas turbine flow meters should have a maximum permissible relative error of 1% over the higher flow range (from 0.2Qmax to Q max ), in the lower flow range ( Qmin to 0.2Qmax ) the maximum permissible relative error is 2%. Usually the linearity of k factors, in percent, is used to express the basic relative error of a gas turbine meter. That means in the higher flow range the gas turbine meters shall have maximum permissible linearity of 1%, and in the lower flow range the gas turbine meters shall have maximum permissible linearity of 2%. The method commonly used to determine the mean k factor, K0 , is: At first, the values of Kmax and Kmin are found out in the higher flow range, and then the mean K factor, K0 , is calculated. Finally, the maximum deviation of K factors from K0 in the higher and lower flow ranges are evaluated to make an error judgment. In some cases this method might introduce a bias error into the K0, because the shapes of K factor signature curves ( the different modes of K factors distribution in different flow range) were not considered. Therefore, it is necessary to make different corrections for K0 in different cases. Our approaches are as follows: When Kmin appears in the lower flow range and the Kmax appears in the higher flow range, K0 (A Kmax + Kmin )/2, here A1.0099 When the Kmax appears in the lower flow range and the Kmin appears in the higher flow range, K0 (B Kmax + Kmin )/2,here B0.9902 When both the Kmax and the Kmin appear simultaneously in the same lower or higher flow range, K0 (C Kmax + Kmin )/2, here C1.0. During the individual calibration of each turbine meter this method has shown clear positive effects. While consideration was given to meters performance in the higher flow range, the performance of turbine meter in the lower flow range has been improved, therefore, more gas turbine meters are ensured to be up to standard. Based on the European Standard PrEN12261:1998 Turbine Gas Meter, the WME (Weighted Mean Errors ) were calculated. The WME show that this is an easy method to obtain the proper value of mean K factor for gas turbine meter.
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Document ID: 7A1B9F70

Performance Of Orifice Meters In Installations With Headers
Author(s): Wojciech Studzinski
Abstract/Introduction:
Headers commonly used in multirun meter stations can generate a variety of flow profile distortions influencing the measurement error of orifice meters. The experiments conducted at the low pressure air test facility at NOVA Research & Technology Centre covered a range of header configurations used in various meter station designs. The upstream piping configuration included a straight inflow pipe, a single elbow and two elbows in perpendicular planes in two orientations. It was found that some changes in flow configuration through the header and meter runs, as well as modifications to the geometrical dimensions of the header, can result in significant flow measurement errors up to 4.3%. There are some header configurations which provide error free operation of orifice meters. The finding validates concerns that the header effect depends on a particular geometry being used and is difficult for an up front assessment at the design stage.
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Document ID: 0A44E440

Twenty-Five Years Of Flow Lab Comparisons Using Tandems Meter Transfer Standards: Lessons Learned And Lessons Not Learned
Author(s): G. E. Mattingly
Abstract/Introduction:
At the first FLOMEKO in 1978, in Groningen, the Netherlands, the author with his NBS co-authors and his UK counterparts presented results from the first known international flow standards comparison using a tandem flow meter transfer standard. This comparison included a testing procedure designed to produce two, statistically independent flow meter calibration results that are typical of the labs normal calibration capability. As such, these results comply with the requirements for the Youden graphical analysis of variance to make conclusions regarding the comparability of the flow standards in the participating labs conducting these tests
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Document ID: C88E3B76

The Matematica Approach
Abstract/Introduction:
1. Optimal Design. 2. Accurate Manufacturing. 3. Optimal installation in tube. 4. Optimal Instrumentation. 5. Calculation of the flow with the Matematica algorithm. makes Scientific Flow measurement in tubes with 0.7 % uncertainty of actual flow from 10 to 100% flow with throat devices possible. Contact Matematica or read this manual to understand how its achieved.
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Document ID: A4EFD1AF

Numerical Simulations Of The Fluid Flow In The Measuring Tube Of The Coriolis Flowmeter
Author(s): Gregor Bobovnik, Joe Kutin, Ivan Bajsic
Abstract/Introduction:
The flow of a viscous fluid through a straight measuring tube of a coriolis flowmeter was investigated using numerical simulations. Numerical simulations were performed by the Comet code, which is based on the finite volume method. The simulations were made for various Reynolds numbers at several vibrating frequencies of the measuring tube. The evolution of the axial velocity, a distortion of the axial velocity profiles, a secondary flow in the measuring tube, and a twisting moment acting on the tubes wall were observed. Values of the twisting moment that acts around the centre of the tubes length were used to evaluate the performance of the flowmeter at different mass flow rates and various dimensions of the measuring tube.
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Document ID: 7B39E381

The Characteristics Of The Straight-Tube Coriolis Flowmeter For Different Lateral Vibration Modes
Author(s): Joe Kutin, Ivan Bajsic
Abstract/Introduction:
1. INTRODUCTION The Coriolis meter is used for measuring the mass flowrate and the density of fluids. Its operation is based on the alteration of the mode shape and the natural frequency of the vibrating measuring tube. This paper is focused on the configuration with a straight and slender measuring tube. In most cases such Coriolis meters make use of the fundamental, i.e. the first lateral vibration mode. However, the higher vibration modes are also under the influence of the same measuring effects, so they can, in general, also be employed. An interesting possibility is represented by a simultaneous application of two or more vibration modes. The measuring results from the additional modes can be used for correcting or identifying undesired effects on the meters operation. As an example, see the patent document 1, which suggests the possibility of eliminating the fluid-pressure effect by taking account of its different influence on two modes
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Document ID: 4B80F3C3

Uncertainty Analysis And Long-Term Stability Investigation Of The German Primary High-Pressure Natural Gas Test Facility Pigsar
Author(s): Wolfram Bremser, Werner Hasselbarth, Uwe Hirlehei, Hans-Jrgen Hotze, Bodo Mickan, Rainer Kramer, Dietrich Dopheide
Abstract/Introduction:
The high-pressure gas flow meter test facility pigsar operated by Ruhrgas AG serves for testing and calibration of turbine-wheel and ultrasonic meters for natural gas in the pressure range between 14 and 50 bar and flow rates ranging from 8 to 6500 m3/h. Pigsar is the national standard of high-pressure natural gas flow under supervision of the German national metrological institute PTB. It represents and disseminates the unified German-Dutch reference value for the unit of volume for high-pressure natural gas. The uncertainty analysis of the test facility presented here was one of the main pre-requisites for the creation of the harmonised reference value.
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Document ID: CD03895A

Demonstration Of Telecalibration Capabilities As A New Tool For Metrology At The German Primary High Pressure Natural Gas Test Facility Pigsar
Author(s): Hans-Jrgen Hotze, Rainer Kramer, Bodo Mickan, Petra Kiesewetter, Dietrich Dopheide
Abstract/Introduction:
The paper demonstrates the telecalibration capabilities of pigsar, the national standard for natural gases at high pressure of Germany. The telecalibration tool was developed in order to give PTB an efficient access to the on-going calibrations at pigsar. It can be considered as a new tool for metrology to maintain and supervise the dissemination of the units volume and mass of natural gases under high pressures. Furthermore, telecalibration is a necessary tool and issue to provide for PTB-certificates based on the harmonized reference value for high-press natural gases as agreed between between NMI-VSL and PTB.
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Document ID: 1EE9A2DF

Unit Of Volume For Natural Gas At Operational Conditions, Ptb And Nmi Vsl Disseminate Harmonized Reference Values
Author(s): M.P. Van Der Beek, I.J. Landheer, Dordrecht,
Abstract/Introduction:
Since November 1999, PTB and NMi VSL have established and disseminate Harmonized Reference Values for the Unit of Volume of Natural Gas 1-6. These Reference Values for Natural Gas at operational conditions are applied, not only in the test facilities at which they originate but are installed and applied as well in other test-facilities 7 and have a wide application in Custody Transfer Measurements 8. The paper describes backgrounds and procedures that have been developed and that are currently in use in Germany and The Netherlands. The prerequisites of the harmonization process, the underlying procedures, results obtained so far as well as the economic benefits for the European market will be pointed out. The harmonization can be considered as the first factual step towards the realization of a European unit of volume for Natural Gas at operational conditions.
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Document ID: 3D3166FA

A Continuous Calorific Value Measuring System Based On A Correlative Method
Author(s): Virginie Van Ranterghem, Gaz De France, Stephane Loubat
Abstract/Introduction:
1. Introduction In the context of the gas market opening up to competition, the number of participants in the gas chain is increasing, exchanges are intensifying and the gas supply sources are multiplying for some parts of the world, notably in Europe where the networks are more and more interconnected. Therefore, it is crucial to be able to better determine the quantities of energy exchanged and the variations in the gas quality, with the view to having more accurate and more equitable billing. The variation over time in the calorific value at a given point in the grid can be as high as a few percent and can have important economic effects. Information on the Wobbe index or the density of the gas is also very useful for some industrial process controls: the Wobbe index variation may have strong effects on the products quality for industries like glassmakers. So important customers are more and more interested in a device able to continuously monitor gas quality variations, as well as the calorific value and the Wobbe index.
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Document ID: 138DB51F

A Most Efficient Diagnostics Tool For Gas Turbine Meters: The Acculert G - II
Author(s): Bertrand Reeb,
Abstract/Introduction:
1. INTRODUCTION Turbine meters are very commonly used for custody transfer in the oil and gas industry. They have been type approved for fiscal metering for decades and in many countries, and they measure each day huge amounts of gas everywhere. While their biggest advantages are their good reliability and a low shift with time, together with a decent rangeability, their main drawbacks are their mechanical fragility and their sensitivity to poor installation conditions. Indeed, a too severe pressurisation might damage the thrust block of the rotor. A disturbed incoming flow profile will also induce an additional error from the turbine meter, which is designed for fully developed turbulent flow profiles. Unlike new categories of meters, such as ultrasonic or Coriolis meters, turbine meters are not furnished with built-in electronics. So they dont offer any diagnostics features by themselves. The AccuLERT G-II was designed to enhance turbine meters by providing a very efficient and easy means to monitor the metrological performances of turbine meters.
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Document ID: F36C08DA

The Biggest Calibration Facility To Be Built For Actual Natural Gas In China
Author(s): Guo Liang, Zheng Qi, Guo Mingchang, Xiao Di, Guo Dianjie
Abstract/Introduction:
In order to meet the requirement of rapid development of natural gas industry, and to calibrate natural gas flowmeter used in the project of west-east natural gas transportation in China, a natural gas flow calibration station (facility) with high pressure and big diameter of pipe will be designed and built in Nanjing city. So far, the location of the calibration station, the design scheme and the process flow has been decided. The conceptual design for the facility has been completed. The main specifications of the facility are as follows: the maximum operating pressure is 5.5MPa, the maximum flowrate under actual working condition is 12000m3/h, the uncertainty of measurement is 0.5% and the maximum diameter of the test flowmeter is 400mm. The facility is composed of the primary standard, transfer standard, working standard, check standard, calibration-test section, steady pressure and flow systems. The primary standard is mass (gravimetric)-time (Mt) primary standard. The transferring standard is sonic venturi nozzles. The high accuracy of turbine flowmeters in parallel is used as for working standard. The ultrasonic flow meters are used as check standard
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Document ID: CA35DEBE

Numerical Simulation Of The Smmi Flow Conditioner
Author(s): Julien Cancade, Bertrand Reeb,
Abstract/Introduction:
1 Context and Introduction Turbine meters and orifice plates are designed to operate in ideal conditions, downstream of straight pipe lengths and therefore turbine meters are calibrated in this configuration. The metering accuracy strongly depends on the flow conditions encountered at the meter inlet. Turbine meters are very sensitive to installation effects inducing flow perturbations like jet flow or swirling effects, generated by pressure regulators or pipe configuration in city gate stations. The error due to bad installation effects can reach more than 3%.
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Document ID: 95DED18C

Efficiency Of The Smmi Insertion Flow Conditioner
Author(s): Julien Cancade, Bertrand Reeb
Abstract/Introduction:
1 Context and Introduction Turbine meters and orifice plates are designed to operate in ideal conditions, downstream of straight pipe lengths and therefore turbine meters are calibrated in this configuration. The metering accuracy strongly depends on the flow conditions encountered at the meter inlet. Turbine meters are very sensitive to installation effects inducing flow perturbations like jet flow or swirling effects, generated by pressure regulators or pipe configuration in city gate stations. The error due to bad installation effects can reach more than 3%
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Document ID: 6C514B46

Calibration Of Large High Pressure V-Cone Flowmeters At High Reynolds Numbers In The CEESI Iowa Natural Gas Test Facility
Author(s): Steve Caldwell, Tom Kegel
Abstract/Introduction:
Synopsis: The paper will describe the testing of 18(457mm) to 28(711mm) VCone Meters over a wide Reynolds Number range to determine the Discharge Coefficients. These results will be presented in graphical form. The tests were undertaken in the CEESI Iowa Natural Gas Test Facility and details of this laboratory are given in the paper. The calibration philosophy and the uncertainties achieved will be described. The measurement assurance program for this facility was used during these tests and this will be described.
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Document ID: 8527AADB

Development Of A New Calibration Wind Tunnel Within Low Air Velocity Range : 0,05 Up To 2 m.s-1
Author(s): Isabelle Care
Abstract/Introduction:
Industrial needs for measurements of low air velocity can be classified in three categories : - Evaluation of comfort in private or collective building (houses, offices, hospitals, schools, stores, libraries, ) and in vehicles (cars, trucks, trains, planes, ). Actually, the fundamental parameters to qualify comfort are air velocity, temperature and humidity. - Control of products quality in industrial processes (clean rooms for microelectronics industries, climatic chambers for aging tests, drying chambers for food industries, ) - Control of equipment to ensure safety of people in hospitals, in pharmaceutical industries, in painting processes,
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Document ID: 3C88F00C

Realisation Of A Mass Flow Measurement Device For A New Reference Gas Calorimeter
Author(s): P. Ulbig, A. Benito, P. L. Cremonesi, J.-R. Filtz, R. Forster, F. Haloua, B. Hay, m. Jaeschke, S. Loubat, S. Sarge, P. Wenz
Abstract/Introduction:
1. Introduction As to fossil energy sources, gas consumption has still the strongest growth rate and has more than doubled world-wide since 1973. In 1999, the production and consumption of gas amounted globally to 2,2 billions of cubic metres. According to estimates of the World Gas Association, gas consumption will increase by an annual rate of 2,3 % until 2030 1. In view of the wid e growing global demand for natural gas and the liberalisation of the gas market in Europe, the measurement accuracy is of decisive importance when determining the calorific value to ensure transparency on the European gas market. At the moment, however, only a few research institutes all over the world are able to determine the calorific value of gases with an expanded measurement uncertainty 0,2%. This applies not only to the determination of the calorific values of pure gases but also to the determination of the calorific value of synthetic and natural gas mixtures.
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Document ID: A0E4598F

Quality Control Program Of The CEESI Ventura Calibration Facility
Author(s): Thomas Kegel
Abstract/Introduction:
The CEESI Iowa Quality Control program is made up of three parts. The first part addresses management issues as described in the ISO 9000 series of standards. It consists of the documented procedures and policies that govern the day to day operations. The second part addresses technical issues as described in the ISO 17025 standard. Examples include uncertainty analyses, calibration records and software verification. The Measurement Assurance Program (MAP) is the third part of the CEESI Iowa Quality Control program. This paper discusses the components of the CEESI Iowa MAP.
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Document ID: 1719116D

Development Of The Pvtt System For Very Low Gas Flow Rates
Author(s): Shin-Ichi Nakao, Yoshiya Terao, Masaki Takamoto
Abstract/Introduction:
The new PVTt system as the standard for gas flow rate less than 5 mg/min has been constructed. This system has three unique aspects for a calibration of gas flow meters. In a PVTt system, the pressure downstream of a device under test (DUT) increases after a flow is diverted to a constant volume tank (CVT) side. It results in a change of a differential pressure working on DUT and a flow rate through DUT changes. Therfore, a flow meter which does not have a function to produce a constant flow rate can not be calibrated by a PVTt system. In this system, by introducing the automatic pressure controller (APC) to control a pressure downstream of DUT and to keep the differential pressure constant, any type of gas flow meters can be calibrated by the PVTt system. Also, as the initial condition in the dead volume uses as a trigger to stop a measurement, the initial and the final conditions in the dead are very close to each other so that the mass correction in the dead volume is not serious and does not need in some cases. And the third aspect is that the mass flow rate through DUT can be directly calculated from the changing rate of the pressure in the CVT at every moment. The CVT that cupper wool is stuffed has a characteristics like an adiabatic tank so that the temperature change in the CVT is very small, about 0.02 K/h during a measurement. The relative standard uncertainty of the PVTt system with these new aspects is 0.1 - 0.05 percent on mass flow rates between 0.1 mg/min and 5mg/min for present.
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Document ID: BF1FA0BF

Influence Of Flow Conditions On An Ultrasonic Flow Meter
Author(s): Olivier Broca, Jol Escande, Bruno Delennegerard Mouton, Pierre Gajan, Alain Strzelecki
Abstract/Introduction:
Multipath ultrasonic flow meters have been more and more used in gas industry for the last ten years, this technology represents an interesting alternative to orifice and turbine meters. In fact, ultrasonic meters offer significant advantages such as bi-directionality, low pressure loss, large range and self-checking capabilities. Nevertheless, in some specific configurations, ultrasonic meters are still sensitive to the installation conditions. During the last decade, this topic has been widely investigated on several aspects, however many questions still remain.
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Document ID: 4DB268C1

Testing The Performance Of Ultrasonic Single Path Hot- Tap Flow Meters
Author(s): G.J. Van Essen, S. Bakker, H.J. Dane
Abstract/Introduction:
1 INTRODUCTION In its gas transmission system Gasunie Transport Services (in this paper further called Gasunie) uses hot-tap single path ultrasonic meters for process control purposes. For these meters, a number of minimal requirements has been established, relating to meter performance (accuracy, response time, reliability, output signals), operating conditions (gas properties, mechanical, environmental and safety requirements) and documentation (manufacturing log, hot-tap procedures).
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Document ID: 0A6D1F18

Confidence Levels Of Measurement Based Decisions
Author(s): Jos G.M. Van Der Grinten
Abstract/Introduction:
Metrological decisions are based on measurements that have uncertainties. Examples are car velocity measurements for law enforcement, initial verifications that lead to the decision to approve or reject an instrument, and the significance of differences found during intercomparisons. The paper shows for each of these examples the relationship between acceptance criterion, tolerance, uncertainty and confidence level. From the discussion of these examples it can be concluded that uncertainties must be known in order to evaluate the risk on an erroneous decision. Confidence levels are associated with decisions for which it is impossible to achieve 100% confidence. Conformance and non-conformance are not two complementary notions. If the accepted risk on an erroneous decision is less than 50% there is a range of observations for which the instrument is not conforming and not non-conforming at the same time. For verifications an increasing number of verification points leads to an increased risk of making an incorrect decision. In order to appreciate the extra information of more observations a curve fit procedure described by Van der Grinten and Peters 1 can be followed. If there are sufficient data, i.e. at least 6 degrees of freedom, it is best to make a curve fit with a 95% confidence envelope. In all of the above-discussed examples the statistical distribution of the observed results is not known. So the risk analysis is based on the assumption of a Gaussian distribution of the measurement results that is the worst-case representation of our knowledge. If other distributions can be demonstrated to describe the measurement results this will certainly lead to a higher degree of confidence or acceptance criteria that are closer to the tolerances.
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Document ID: 333238D1

The Compliance Test For Flow Conditioners As Applied To A Zanker Flow Conditioner Plate With A Venturi Tube
Author(s): Michael Reader-Harris, Bill Brunton, Ian Nicholson, Ronnie Rushworth, David Hodges
Abstract/Introduction:
This paper describes the test work undertaken to establish that the compliance test in ISO 5167- 1:2003 is satisfactory for Venturi tubes and also to determine the required upstream lengths when a Zanker Flow Conditioner Plate is installed upstream of a Venturi tube. In essence the Zanker Flow Conditioner Plate met the compliance test upstream of a Venturi tube provided that there is at least 3D between the plate and the upstream pressure tapping of the Venturi tube and 7D between the plate and any upstream fitting. However, if the compliance test were to apply to flow conditioners with Venturi tubes at high Reynolds number, it is worth noting that the shift in discharge coefficient due to a flow conditioner does not have a single value for all ReD 3 106. Moreover, the requirements of the compliance test in terms of range of friction factor may be too restrictive
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Document ID: 3A640FFB

The Use Of Ultrasonic Gas Flow Metering Technology For The Development Of Accurate Energy Meters For Natural Gas
Author(s): Henk Jan Panneman, Cornelis W. Koreman, Sjoerd Toonstra, Floris Huijsmans
Abstract/Introduction:
1. Introduction Gasunie Research gained their years of experience in efficient energy utilization, gas transport and gas measurement as the in-house laboratory for N.V. Nederlandse Gasunie. This company, which was an integrated gas transport and trading company until the beginning of 2002, has been one of the largest gas suppliers in Europe for several decades. As part of this company, Gasunie Research has always striven to guarantee the continuity of the gas supply, to ensure the safety of gas transport and to enhance the added value of natural gas as a fuel. Gasunie Research developed a wealth of new technology for domestic, commercial and industrial end users, and for the energy sector itself. The expertise that Gasunie Research has acquired through these activities and the years of practical experience is now made available to third parties.
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Document ID: 946BAF1A

Effect Of Gas Type On The Thermal Properties Of Small Sonic Nozzles
Author(s): Noel Bignell
Abstract/Introduction:
A previous study (Bignell and Choi, Flow Meas. & Instrum. 13 (2002) 17-22) of the effect of temperature on the coefficient used to characterise small sonic nozzles is reviewed. Adiabatic cooling of the gas stream in the throat causes the body of nozzles to be cooled but a heater and temperature control system allow the temperature of the nozzle to be held constant. Using a gas flow standard that can operate in continuous mode, measurements were made of nozzle coefficients at different temperatures using air, argon, nitrogen and carbon dioxide. The nozzle coefficient changes with the gas type and linearly with the temperature of the body of the nozzle. The first of these changes is explained by changes in the real gas correction factor for argon but not for carbon dioxide. The temperature changes are much greater than those due to the area, the discharge coefficient and the real gas correction factor. It is necessary to invoke the properties of the thermal boundary layer to explain these changes, which are found to be greater for gases having a higher specific heat ratio. Keywords: sonic nozzle critical flow standards boundary laye
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Document ID: 9F89F389

Practical Experience On Inspections Of Orifice Plates Measurement Systems For Natural Gas
Author(s): Kazuto Kawakita
Abstract/Introduction:
Flow Metering Systems Everyday, in many countries producers and importers supply larg e volumes of natural gas produced from domestic fields or purchased abroad. To attend to this need, a whole host of interlinked and coordinated activities and technical installations are required both on the purchase and the sales side. Besides the production and processing facilities, compression stations, transmission and distribution pipelines, operation and control stations, many measuring systems are necessary to quantify the huge volumes of gas commercialized among parts
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Document ID: C26280BE

Principle Of Converting The Mechanical Movements To Electrical Signals By Turbine Meters
Author(s): Hakan Kaykisizli, Dr.Vahit ifti, Ernur Karadogan, Basak Akselli
Abstract/Introduction:
Turbine meter is a flow measurement device utilizes the angular velocity of rotating blades to measure the flow rate. Pulses for a known time period are counted by turbine meter counting mechanism. The total number of counts for a given time period is proportional to the volumetric flow rate of the turbine meter. National Metrology Institute of Turkey (UME) standard reference turbine meter pulse information is generated by a system called variable reluctance tachogenerator. This paper explains how mechanical movements of blades are converted to electrical signals and comparing the degree of conformity between the theoretical and experimental results. Meter factor k is utilised to compare experimental and theoretical results. Geometrical calculations and experimental results from the UME reference turbine meter are compared. Vector analysis of the forces acting on the blades showed that blades are moving slower than their geometrically predicted velocity. This is explained by effect of retarding torques on the exit velocity of the fluid
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Document ID: E33C7522

The Application Of Mems Technology To On-Line Analyzers For Natural Gas
Author(s): Ir. Johan Bats
Abstract/Introduction:
Process Gas Chromatographs have been in use in the natural gas industry since the early eighties. The core analytical elements are commonly manufactured with conventional fine-mechanical tools. Recently MEMS technology has opened the doors to a new level of performance for on-line natural gas analysis.
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Document ID: 0FAC0A4A

Improving Vortex Flow Metering Using Ultrasound
Author(s): Volker Hans
Abstract/Introduction:
Commercial vortex flowmeters use the well-known effect of Karman vortex street. The frequency of vortices generated in the wake of a bluff body is proportional to the average flow velocity. Usually it is detected by pressure sensors which are not very sensitive. Therefore bluff bodies of big sizes are required. An alternative method to detect the vortices in the streaming fluid is to use a high sensitive ultrasonic wave which is complex modulated. The demodulation can be executed by digital signal processing. Small sizes of bluff bodies can be realized. The bluff body size and the carrier frequency must be harmonized.
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Document ID: 331346AE

What Is The Best Transfer Standard For Gas Flow?
Author(s): John D. Wright
Abstract/Introduction:
NIST is serving as the pilot laboratory for an international key comparison (KC) in low - pressure gas flow and we are in the process of designing the transfer standard to be used. This paper covers a wide range of topics related to the design of the transfer standard for the KC.
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Document ID: 82F3CC7C

Spin-Offs From The Development Of Rotary Gas Meters
Author(s): Ing J.T.M. Bergervoet
Abstract/Introduction:
: The basic principle of a rotary gas meter consists of two rotors in the form of a figure -8 that rotate inside each other with the precision of a gear wheel. The outer edges of these rotors turn in a very close fitting measurement chamber. The outer edges of the turning rotors transfer fixed quantities of gas from the inlet to the outlet like small buckets. Because the radii of the sealed streams in the middle between the two rotors always vary there is a discontinuous volume of gas passing per angle revolution of the rotors. The shape of variation is near a sinus and the frequency is four times the frequency of the rotor revolution and the amplitude is near 12% of the average flow. These variations give an irregular rotating of the rotor at low flows and pressure and flow pulsations at higher flows. These pulsations can lead to resonances in the installation where they are mounted in. This can give sound problems and mis-indication of the rotary gas meter itself or to other devices in the installation.
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Document ID: 00ACCED0

Realisation Of Compact Metering Runs With Ultrasonic Gas Flow Meters And Reducing Measurement Uncertainty.
Author(s): Koen H. Commissaris
Abstract/Introduction:
1 This paper presents the results of the application of an ultrasonic gas flow meter in combination with a flow conditioner. This development aims at both reducing measurement uncertainty and the possibility of realising compact (short) metering runs, requiring less investment in piping and installation while maintaining good accuracy.
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Document ID: 5BDAA568

Wib - Working-Party On Instrument Behaviour Werkgroup( Voor Instrument Beoordeling)
Author(s): Tom Kuperij
Abstract/Introduction:
In 1962, five leading Dutch process industries (BPM now Shell, Algemene Kunstzijde Unie now AKZO, DSM, Hoogovens now Corus and Unilever) got together to explore combining tests and sharing the results on process instrumentation. Companies were at the time carrying out these activities individually at very high costs. The five concluded that sharing instrument evaluation reports, even with direct competitors, would be to the benefit of all. A follow-up meeting held on the 16th December 1963 resulted in the formation of a co -operation panel under the Dutch name Werkgroup voor Instrument Beoordeling, shortened to WIB. An independent laboratory, the Institute for Applied Physical Research -TNO, was approached and asked to carry out testing on behalf of WIB. TNO was also made responsible for the administration of the association, supervised by a Board of WIB members. WIB activities attracted high interest from companies abroad wanting to join and a few years later the official language became English. WIB was translated into Working-party on Instrument Behaviour. It was officially registered as a non- profit association in 1968.
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Document ID: C40CAF38

New Primary Standard For Hydrocarbon Flowmeters At Nmij - International Comparison Between Nmij And Sp -
Author(s): Takashi Shimada, Ryouji Doihara, Yoshiya Terao, Masaki Takamoto, Krister Stolt, Anders Andersson,
Abstract/Introduction:
A new primary standard for hydrocarbon flow measurements has been constructed at NMIJ, National Metrology Institute of Japan. The facility is designed for the calibration of hydrocarbon flowmeters in the flow rate range between 3 to 300 m3/h with an expanded uncertainty better than 0.04 % for volumetric flow rates and 0.03 % for mass flow rates (coverage factor: k2). The primary standard applies a static and gravimetric method with flying start and finish. The facility consists of two test rigs with kerosene and light oil as working fluid. The test lines for flowmeters are 50, 100 and 150 mm in diameter, and light oil and kerosene are used as the working fluids. A small volume prover and servo PD meters are used as working standards. This calibration facility has special features that enable highly accurate calibration. The uncertainty of calibration for flowmeters has been roughly estimated. As a result, the estimated uncertainty is shown to be less than the target uncertainty. The dominant sources of combined uncertainty of flow rate are uncertainties in the measurements of the mass of oil in the weighing tank and the density of oil through the flowmeter under test. To verify the performance of this oil calibration facility at NMIJ, an international comparison with SP, Swedish National Testing Research Institute , has been carried out. A screw-type positive displacement flowmeter was selected as the transfer standard and was calibrated at NMIJ and SP . The result shows that the two national standards at the two institutes agree within the quoted expanded uncertainties.
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Document ID: 9038F6AF

Comparative Performance Evaluation By Wib Of Two-Wire And Four-Wire Emf Meters Of Three Different Makes
Author(s): Frans Van Laak
Abstract/Introduction:
1 Introduction The present comparative performance evaluation has been conducted for the following reasons. 1.1 Two-wire vs. four-wire systems In the chemical, petrochemical and various other industries, the two-wire system is used as the standard infrastructure for field instruments (other than analysers). This means that instrument signals are transmitted and power is supplied through the same two wires. Exceptions to this practice relate to four-wire flow meters such as the following: EMF meters Ultrasonic meters Coriolis mass meters
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Document ID: 552969E6

Study Of Water Flow Calibration Facilities With Multi-Function And High Accuracy
Author(s): Hongjun Sun, Chao Wang
Abstract/Introduction:
The paper describes a water flow calibration facility combined weighing method and master meter method. The flowmeter calibration system aims at obtaining a very high level of accuracy and assurance of product reliability. Moreover, a new method, synchronous pulse counting method, to improve the calibration accuracy and efficiency of master meter method is proposed. Experimental results show that the computer control system is reliable and the accuracy using weight method and master meter method is up to 0.066% and 0.076%, respectively.
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Document ID: D1829E9B

A Current-Type Electromagnetic Flowmeter For Two-Phase Flow
Author(s): Yeh-Chan Ahna, Ung Do Ohb, Moo Hwan Kimc
Abstract/Introduction:
The theory for the current-sensing electromagnetic flowmeter was newly developed. The current-sensing flowmeter has a high temporal resolution so that it can be applied to measure the flows with fast transients like two-phase flow. The signal prediction and the calibration of the current-sensing flowmeter in two-phase flow and the measuring of the characteristics of two-phase flow are the major concerns. To do this, using a finite difference method, the three-dimensional virtual potential distributions for the electrodes of finite size were calculated for single-phase flow, annular flow and slug flow. With the gradient of the virtual potential, the rectilinear weight functions for the single-phase flow and the annular flow which were the main parameter for the conventional voltage-sensing flowmeter were deduced and compared with existing analytic solutions for the point-electrode. There was a reasonable correspondence between the present and existing results. Particularly the axial weight function and the radial weight function for single-phase flow, annular flow and slug flow were newly defined and computed by taking the gradient of the virtual potential. The flow pattern coefficient f was introduced to simplify the calibration process for two-phase flow. It was calculated from the solved virtual potential distributions of single-phase and two-phase flow. For annular flow, the coefficient was well-fitted with two decaying exponential functions of the normalized film thickness d*, f1+1.3 exp(-7d*)+7.3 exp(-31d*). For the slug flow, it was provided as a function of the normalized film thickness d* and the normalized position of a slug bubble tail L*. The coefficient by the numerical simulation was compared with experimental results obtained by Frequency Response Analyzer (FRA) and Potentiostat/Galvanostat. The comparison clearly showed the agreement between the numerical and the experimental results.
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Document ID: 5EF4C858

Novel Technique For Calibration Pipe Prover Measuring Volume
Author(s): Helmut Tbben
Abstract/Introduction:
The measuring volume of a pipe prover used as a volumetric standard measuring device in the hydrodynamic test field was calibrated by a geometrical measuring method, having been implemented for the first time. Using incremental length measuring devices for the axial and lateral direction a more precise characte rization of the volume is feasible.
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Document ID: 1761F46B

Development Of A New Type Of Coriolis Flowmeter With Independent Vibration Frames For Drive And Torsion
Author(s): Ryouji Doihara, Yoshiya Terao, Masaki Takamoto
Abstract/Introduction:
A new design concept for improving the sensitivity of a Coriolis flowmeter is proposed. The differences between the developed flowmeter and current commercial products lie in adoption of acceleration sensors and reinforcement frames. These features impart an interesting characteristic: sensitivity improves with increasing drive frequency. A flow tube has been fabricated on the basis of the new design concept, and subjected to basic experiments in order to confirm the characteristics of the measurement system. Although some problems still remain, the characteristics have been partially confirmed.
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Document ID: 0E43A457

Experiences Of Pulp Flow Measurements With Electromagnetic Flowmeters
Author(s): Esa Luntta, Harri Nystedt, Jouko Halttunen, Juha Kortelainen
Abstract/Introduction:
Electromagnetic flowmeters are today practically the only meter type used in the measurement of pulp flows in paper mills. Usually, these meters have the required accuracy (or at least they are believed to have), the price of them is reasonable, and they are almost maintenance-free. However, electromagnetic flowmeters are usually calibrated in water flow and the effect of the change of the flowing medium to pulp on the accuracy has been investigated rather little 1, 2, 3. The possible error sources in pulp flow measurements can be for example non-uniformity of conductivity or air content of pulp suspension. Incomplete mixing of dilution water may also affect the measurement accuracy. Moreover, the position of the flowmeter has to be selected often after the process plant has been built up. Therefore, the disturbance -free pipe lengths upstream and downstream of the meters can be too short. This paper presents the results of the experiments carried out with five electromagnetic flowmeters of different manufacturers with different water and pulp flows.
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Document ID: AB63B667

New-Design Dual-Balance Gravimetric Reference System With Ptbs New Hydrodynamic Test Field
Author(s): Rainer Engel, Ptb Braunschweig, Hans-Joachim Baade, Droege Baade
Abstract/Introduction:
PTBs new Hydrodynamic Test Field, which represents a high-accuracy water flow calibration facility, will serve as the national primary standard for flow measurands: volumetric and mass flow rate, respectively, and total flow measurement, i.e. the quantity of fluid (volume or mass) passing a flowmeter. As most accuracy determining component parts, it comprises three different-size dual-balance gravimetric reference systems: 300 kg, 3 tons and 30 tons. This type of gravimetric references were realized as a combination of a strain gauge based and electromagnetic forcecompensation load cell based balance, each. Though each of these two weighing principles fulfils the individual accuracy requirements that have been derived from the total measurement uncertainty budget of the calibration facility as a whole, the electromagnetic force-compensation load cells reveal several advantages concerning linearity error, hysteresis error and sensitivity.
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Document ID: 4A596485

Velocity Measurement In Boiler Tubes Using A Novel Ultrasonic Flow Measurement Technique.
Author(s): Prof. m. L. Sanderson, Dr. R. H. Al-Rabeh
Abstract/Introduction:
A method is reported here for the ultrasonic measurement of flow in boiler super-heater tubes. The tubes are in a tube bank formation running at high temperature (typically 300C) and pressure (typically 100bar). To enhance heat transfer, the tubes in this application are ribbed internally with thick helical ribs. Further, all measurements have to be made on one side of the tube bank to avoid direct radiation on the fire side. Conventional ultrasound methods are difficult to apply in these conditions. The combination of thick steel walls, internal ribbing and the substantial temperature and density gradients do not provide for a well defined sound beam path. Instead a new method is proposed to measure the flow rate using the properties of the frequency spectrum of the noise imposed on the sound beam by random fluctuations in the velocity and density of the fluid caused by the nature of the flow in such tubes.
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Document ID: 60C28F76

Numerical Modelling Of Vortices Development In Tapered Duct
Author(s): Grzegorz L. Pankanin, Jerzy Berlinski, Ryszard Chmielewski
Abstract/Introduction:
The work refers to the vortex flow meter optimisation. Searching of the optimal geometry of the meter became the fundamental task for designers. For many years their attention has been focused mainly on the bluff body as well as on the sensor designing. Numerous experiments made by authors of the paper confirm that not only the bluff body shape but also geometry of the duct impacts the vortices development. Duct walls stabilize the vortex shedding and its development process. Hence the conception of flow duct tapering in the vortices development zone. On the basis of the numerical simulation it is concluded that due to the pipe cross-section contraction (causing the flow velocity increase) the vortex rotation energy enhancement as well as vortex life-time increase has been attained.
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Document ID: 49D394AD

Flow Sensors Of Heat Meters For Thermal Solar Systems
Abstract/Introduction:
For measurements of thermal energy, produced by thermal solar systems, heat meters, installed in collector circuits of solar systems, must be qualified for the most used propylene glycol-watermixtures as heat conveying liquid. In the project, sponsored by the Deutsche Bundesstiftung Umwelt (DBU) and the heat meter industry, the accuracy of several types of flow sensors at nominal flow rates between 0.6 m/h and 1.5 m/h had been investigated using propylene glycolwater- mixtures.
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Document ID: 7288C106

Closure Model For Two-Phase Liquid-Gas Measurement Under Slug Flow Conditions
Author(s): S.Al-lababidi, Prof. M.L.Sanderson
Abstract/Introduction:
A series of experiments has been undertaken to investigate the behaviour and the performance of a clamp-on transit-time ultrasonic flowmeter in two-phase air/water flow. The results show the performance of the liquid ultrasonic meter to be seriously affected by the presence of free gas in a manner that is dependent on the actual flowrate of the gas and the flow regime. The data presented here covers water/air flow under slug flow regime and an evaluation of transit-time ultrasonic meter and its suitability for two-phase flow measurements. The factors affecting performance are discussed and a closure method using a transit-time ultrasonic flowmeter is introduced.
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Document ID: 9B812FA5

Flomeko 2003 - Paper 136 ISO 17025 Accreditation For A Standing Start Finish Ssf() Primary Flow Stand And The Application To Using Coriolis Flowmeters As Reference Standards
Author(s): Mark Lee
Abstract/Introduction:
At FLOMEKO 2000 Micro Motion, Inc. (MMI) reviewed the concept of Transfer Standard Method (TSM) flow stands for the calibration of flow instruments, in particular the uncertainty analysis for calibration of Coriolis meters. This paper is an extension of the topic, discussing in depth the issues involved with ISO 17025 accreditation, maintaining calibrations, and traceability.
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Document ID: 3589F084

Flomeko 2003 - Paper 137 Field Proving By Micro Motion Coriolis Prover Mass Master Meter Method
Author(s): Bert Roos, Milovan Antonijevic
Abstract/Introduction:
Coriolis Mass Flow Meters have been used for process optimisation for more than 20 years. Refining, petrochemical, and other process industry for use in automating and optimising production processes have adopted this technology. As companies have gained more confidence and trust in Coriolis technology it was only natural that they began to apply them in fiscal service or custody transfer metering. Coriolis inherent reliability and meter factor stability as well as multi-variable versatility (mass, density, operating volume, and temperature) have helped many users lower life cycle costs and better manage loss control.
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Document ID: C48A2890

Theoretical Self-Error-Cancelling Diverters For Liquid Flow Calibration Facalities
Author(s): Tsyh-Tyan Yeh, Nhlanhla P. Yende, Pedro I. Espina
Abstract/Introduction:
A design for diverter valves in gravimetric liquid flow calibration facilities is examined. The concept makes use of repeated unidirectional motions of the diverter valve to reduce errors associated with asymmetry in the diverter valve motion and in the liquid jet velocity profile. Various implementation examples are provided and their benefits are discussed. The experimental results, given in a different paper 1, confirm the good performance of the error free diverter design. This new diverter design has been incorporated in the new NIST calibration facility 2.
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Document ID: CD79F3AF

The New NIST Water Flow Calibration Facility
Author(s): Vikram, Gowda, Tsyh-Tyan Yeh, Pedro I. Espina, Nhlanhla P. Yende
Abstract/Introduction:
A static-gravimetric liquid flow calibration facility is under construction at the NIST Gaithersburg Campus. The facility is designed to calibrate flow meters from 25 mm to 400 mm in diameter, at flow rates from 8 L/min to 38,000 L/min. It incorporates a diverter valve design, which greatly reduces the uncertainty associated with the flow diversion into the collection tank. This paper details design and construction novelties of the system and outlines the expected uncertainty budget for the calibration facility.
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Document ID: 1F8A72C3

A New Generation Of Inline Liquid Ultrasonic Flow Meters
Author(s): Jankees Hogendoorn, Herman Hofstede, Andre Boer, Helen Danen
Abstract/Introduction:
The ultrasonic flow meter market has developed rapidly and has seen a significant growth. Due to its high performance and unique properties, ultrasonic flow meters have built up a prominent position in the flow meter market and in many industrial processes. Reputed market research companies claim that the ultrasonic flow meter market is the fastest growing market and expect further explosive market growth.
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Document ID: 15574CC3

Calibration Of The Sluice Gates In The Afsluitdijk
Author(s): Ivo Pothof, Christof Lubbers
Abstract/Introduction:
The Afsluitdijk (literally Closing Dike) has been constructed in 1932. The objectives of the dike were flood protection, an area increase for agriculture and a fresh water reservoir (IJssel Lake). The Afsluitdijk comprises two sluice gate structures: the Stevin sluice gates (15 gates) at the West end of the dike and the Lorentz sluice gates (10 gates) at the East end of the dike. Every low tide with Wadden Sea levels sufficiently below the IJssel Lake level, the gates open and fresh water flows into the Wadden Sea. Rising sea levels, bottom depletion and climate change result in decreased discharge capacity. Therefore an additional sluice structure is planned. The discharge coefficients of each of the 12 m wide gates are still based on physical models from 1922 (Karlsruhe), 1927 and 1933 (Delft) with an estimated uncertainty of 20%. A more accurate determination of the discharge capacity of the sluice gate structures is required to establish the design capacity and associated cost of the new structure. Therefore the Ministry of Transport, Public Works and Water Management, Water Management Direction (RWS) has decided to calibrate the sluice gate structures in the Afsluitdijk, aiming for an uncertainty of 5%. The calibration project is carried out by RWS with support from WL Delft Hydraulics. RWS carries out the water level and velocity measurements and develops software for primary evaluation and time synchronisation of the data. WL Delft Hydraulics has developed the calibration method and the uncertainty evaluation for this particular construction, in close co-operation with RWS. Furthermore, WL has performed statistical analyses. First the global geometry, the typical operation and the possible flow regimes are outlined. Then the instrumentation and approach of the calibration are discussed. The approach requires calibration of the layers near the bottom, the walls and, especially, the water surface. These calibrations are discussed in more detail. Finally an estimate of the total uncertainty of the calibrated discharge through a sluice gate in the Afsluitdijk is given.
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Document ID: 869261F0