Vikram. Gowda, Tsyh-Tyan Yeh, Pedro I. Espina, Nhlanhla P. Yende
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.
Tsyh-Tyan Yeh, Nhlanhla P. Yende, Pedro I. Espina
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, confirm the good performance of the error free diverter design. This new diverter design has been incorporated in the new NIST calibration facility.
Bert Roos, Milovan Antonijevic
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...
Mark Lee, Aart Pruysen
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. The company has chosen to use Coriolis flowmeters as Global Reference Meters (GRM) to maintain the traceability on the TSM stands operating worldwide. To accomplish this ISO 17025 accreditation was successfully sought...
Aart Pruysen
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%. The biggest scale of this facility, a 24000 kg scale for flowcapacities up till 660 t / h and based on gyroscopic balance, is calibrated since three years via a Coriolis MicroMotion mass master meter. The reason for this method is that placing 3 times 24 * 1 ton...
E. van Bokhorst, M. C. A. M. Peters, F. M. Braal
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. International standards like ISO, AGA and API, available for several flowmeter principles, sometimes refer to swirl, flow and piping dynamic effects, though they do not specify allowable amplitudes or frequencies....
Rainer Engel, Hans-Joachim Baade, Andreas Rubel
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...
Tong Meng, Ren Ping, Chen Ming
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 pipe’s support are investigated. It’s presented the FEM calculations are agreed with the theory...
M. Pusayatanont, E. H. Higham, P. J. Unsworth
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....
M. Pusayatanont, E. H. Higham, P. J. Unsworth
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...