J. Liu, T. Wang, Y. Yan, X. Wang
Coriolis flowmeters are recognised to give excellent performance of the mass flow measurement and independent density measurement of single-phase flow. However, the large measurement error of a Coriolis flowmeter under gas-liquid two-phase flow conditions makes it unsuitable for many industrial processes where gas-liquid two-phase flow is encountered. Although analytical models have been proposed to explain the reasons behind the large output error of a Coriolis flowmeter under two-phase conditions, none of the individual theories nor their combinations can match experimental results to...
A. S. Ribeiro, D. Loureiro, M. C. Almeida, M. G. Cox, J. A. Sousa, M. A. Silva, L. Martins, R. Brito, A. C. Soares
Clean water and sanitation are one of the 17 sustainable development goals (SDG) of the United Nations’ 2030 agenda for action, being directly related to several other objectives, namely, economic growth, sustainable cities’ communities, responsible consumption and production, and climate action. Since demand for this resource is constantly growing, problems of scarcity of water and transboundary issues are becoming critical to increase water supply efficiency and to improve water management in modern society. Water providers make use of large infrastructures – water supply networks –...
L. L. Martins, A. S. Ribeiro, J. Alves e Sousa
This paper is dedicated to the flow-rate measurement uncertainty calculation, considering the use of Pitot tubes inside closed conduits as the applied measurement method, according to the guidelines and procedures established by the current ISO 3966 standard. The performed study aims the comparison between measurement uncertainties obtained by the conventional error approach mentioned in the method’s standard and the results obtained from the application of the Monte Carlo Method (MCM). Using the same input data, a difference of 0,3% was obtained between the 95% relative expanded measurement...
I. A. Isaev, V. A. Fafurin, A. V. Mingaleev, A. I. Gorchev, A. B. Yakovlev, O. Yu. Sladovskaya
The article deals with the basics of metrological support of low-pressure gas (air) flow measurements, describes the improved State (National) Primary Standard GET 118-2017 and methods of reproduction and transfer the gas flow rate units implemented in the Russian Federation. The improved GET 118-2017 is a complex of five test rigs that are interconnected by means of the reference sonic nozzles, which received the unit of measure on the initial test rig TR-1 of bell type. For transfer the gas flow rate units to calibratable sonic nozzles from reference sonic nozzles in GET 118-2017 a new...
Felix Heitmann, Jonas Steinbock, Markus Juling
In thermal power plants, flow meters are operated at high temperatures and pressures and often encounter disturbed flow profiles. This leads to an increased measurement uncertainty, which limits the save operating range of flow rates and hence the plant’s power output. Therefore, the laser optical flow rate standard (LFS) was developed. It is designed to allow the on-site calibration of industrial flow meters in power plants at high temperatures and pressures. It makes use of the metrologically traceable and non-invasive laser Doppler anemometry (LDA) to measure the velocity field...
R. A. Korneev, A. R. Tukhvatullin, V. A. Fafurin, A. V. Shchelchkov, A. I. Ataeva
An indirect method is presented for estimation standard measurement uncertainties included into a standard uncertainty budget by the diverter, reproducing units of mass and volume of fluid in a stream, mass and volumetric flow rates of a fluid.
Yuan Liu, HeMing Hu, Chi Wang, Qisen Miao,Hang Cui
We will investigate the measuring principle of time-of-flight(TOF) ultrasonic level meter, related analysis and comparison of performance and modification method. Higher measuring precision of height at 0.1mm order of magnitude, and algorithm robustness in the case of weak surface movement, are expected. When using absolute transit time algorithm, the head of wave should be clear, by eliminate echo faster than that through main wave path. And in second trace echo case, ensure there are parts of two echo waves, can be located by theoretical arithmetic and waveform algorithm, have higher...
K. Chahine, Z. Wang
A new PVTt standard for gas flow has been commissioned at NMIA, which relies on measurements of pressure, volume, temperature and time. The main aim of developing this new standard was to reduce the ±1000 ppm (±0.10%) uncertainty of measurements made with NMIA’s bell and mercury-sealed piston provers. The uncertainty associated with measuring the mass flowrate using the new PVTt standard is estimated to be ±116 ppm (±0.012%), this significant improvement in uncertainty can be attributed to two reasons. Firstly, the volumes of existing provers at NMIA were measured to no better than ±400 ppm,...
R. Kramer, T. Dietz
The paper describes an ultrasonic flow meter with an axial measuring path, which uses acoustic plane waves propagating through pipes with a sufficiently small diameter. The propagation of plane waves in a circular pipe depends on the pipe diameter and the wavelength of the acoustic signal. Therefor, the design of the meter has to consider the speed of sound for the gases intended to use, e.g. nitrogen, methane, hydrogen and any mixture of these. In order to measure low flow rates with small uncertainties, a great acoustic path length, i.e. a pipe with long length is advantageous. On the...
B. Ünsal, B. Akselli, Ş. Sacı, E. Aksel
Household water meters are tested/calibrated at steady flow conditions however, during their actual usage, flow conditions are not always steady and not so much known about the flow dynamics. The present paper reports about instantaneous flow rate measurements conducted at households to find out what kind of flow rate profiles exist through household meters. From these measurements, 3200 single water consumption events were extracted. Then each single event was analysed to obtain various information such as rise time, fall time, amplitude, event duration and consumed water volume. These...