Optofluidic flow meter for sub–nanoliter per minute flow measurements

Author(s):  
Jalal Sadeghi ◽  
Paul N. Patrone ◽  
Anthony J. Kearsley ◽  
Gregory Cooksey
Keyword(s):  
2014 ◽  
Vol 654 ◽  
pp. 262-265
Author(s):  
Jian Ling Deng ◽  
Yong Zhu ◽  
Zi Li Zhou ◽  
Rong Rong Zhai ◽  
Ji Feng Song ◽  
...  

In this paper, a dual-axis tracking trough solar collector system is established, and used to measure and calibrate flow rate at different conditions by using the ultrasonic flow meter and mass flow meter, providing important reference for follow-up experimental study. With the changing of the medium’s temperature and the rotation speed variation of the pump, the two flow meters were used to work together to measure the accurate flow measurements, obtaining the measurement error of the mass flow meter. After that, the reason of error and methods used to reduce the error are analyzed.


1999 ◽  
Vol 121 (2) ◽  
pp. 422-426 ◽  
Author(s):  
Tore Lo̸land ◽  
Lars R. Sætran ◽  
Robert Olsen ◽  
Inge R. Gran ◽  
Reidar Sakariassen

The ultrasonic flow meter is a newcomer among flow meters for measuring large quantities of natural gas. It has notable advantages compared to traditional meters. The ultrasonic flow meter is much more compact and has a wider dynamic range for flow measurements than the orifice plate meter. When manufactured, the ultrasonic sensors are often set back from the pipe wall in a cavity. When the fluid flows past the cavities, a secondary flow of vortices with characteristic size equal to the cavity width is established inside the cavities. The aim of this study has been to investigate the influence of this secondary flow on the accuracy of the ultrasonic flow meter. Both measurements and numerical simulations of the cavity flow have been conducted. It has been found from the present work, that the influence of the flow in the cavities on the measurements increases nonlinearly with the pipe flow rate.


Author(s):  
M. A. Velichko ◽  
Yu. P. Gladkikh ◽  
O. N. Satler

Objectives. The purpose of the work was to change the method of signal transmission containing metrological information from industrial time-pulse ultrasonic gas flow meter to a compu-ting device (CD). It was planned to expand the range of devices serving as gas flow calculators. A hardware-software complex (HSC) for automatic calibration / verification of ultrasonic flowmeters was to be developed. This HSC should work equally well on different operating systems. The information exchange between the CD and the flowmeter was to be carried out wirelessly.Method. The Wi-Fi Pro-tocol was used as a wireless Protocol. The energy-efficient ESP8266 controller was chosen as micro-controller to provide the functionality of Wi-Fi. The ESP8266 board acted as a Wi-Fi access point on the network to which CD was connected for data exchange. The ESP8266 microcontroller also served as a HTTP server. Exchange of metrological and other information was carried out by GET-requests. Given the need for continuous flow measurements and simultaneous communication between the user and the flow meter, requests to the server were transmitted using AJAX technology. The software part of the APK consisted of 3 programs: a program that measured the flow and transmitted the information further to the ESP8266 microcontroller, a server program recorded in ESP8266, providing a response to the requests of CD users, and the client program installed on the CD. The article discusses the key points of the HSC.Result. As a result of this work, the HSC was processed for calibration/verification of ultrasonic gas flow meters. For the first time this process for industrial flow meters was implemented using the ESP8266Wi-Fi controller as an access point. As a WU, it became possible to use any desktop or laptop computer or mobile device with a modern browser.Conclusion. The method proposed in the paper significantly simplified the data exchange between the VU and the flowmeter, reduced the cost of software development due to the common approach for different operating systems.


2014 ◽  
Vol 40 ◽  
pp. 157-161 ◽  
Author(s):  
Sahand Pirouzpanah ◽  
Muhammet Çevik ◽  
Gerald L. Morrison

1965 ◽  
Vol 5 (7) ◽  
pp. 313-317 ◽  
Author(s):  
John B. Price ◽  
Richard C. Britton ◽  
Lynn M. Peterson ◽  
John W. Reilly ◽  
Arthur B. Voorhees

1996 ◽  
Vol 33 (3) ◽  
pp. 504-509 ◽  
Author(s):  
R Sri Ranjan ◽  
T Karthigesu

The measurement of water flow through clay at low hydraulic gradients (<1) is a very difficult task requiring several months to accomplish in a laboratory. A capillary flow meter, capable of measuring extremely low flow rates through clay samples under low imposed hydraulic gradients, has been designed and tested. Flux as low as 10–12 m·s–1 was successfully measured using this flow meter. To minimize the contaminatiion effects, perchloroethylene, which has self-cleaning ability, mixed with Sudan IV was used as the bubble liquid in the capillary flow meter. Glass and Teflon® valves were fused to the inflow and outflow capillary tubes to permit these components to be flushed with cleaning agents and distilled water. The movement of the menisci through the capillary tube was used as a measure of the volume flow rate through the sample. A sensitive differential pressure transducer was connected between the inflow and outflow end of the clay sample to measure the imposed hydraulic head difference. This flow meter has been independently calibrated against a conventional constant head permeameter. Once the clay samples have stabilized in a permeameter, oedometer, or a triaxial cell, multiple flow measurements under low hydraulic gradients can be done in less than an hour. Key words: nonlinear flow, saturated hydraulic conductivity, non-Darcy flow, ultra-low flow meter.


2019 ◽  
Vol 8 (4) ◽  
pp. 6011-6017

Due to fluid properties, flow patterns, external factors (temperature, pressure, etc.) measurement shows a dynamical characteristic. Therefore, calibration is an indispensable process in order to ensure the standards of flow metering. Ultrasonic flow meters, which are ameliorated the readings over time, are promising devices to minimize the flow measurements error. In this paper, the calibration procedure of a specific ultrasonic water flow meter is discussed, and then a wireless system is proposed to carry out fine calibration. According to the results, piecewise linear least squares approach supplies the best performance at overall volumetric flow rates accompanying with wireless fine calibration system based on RF communication


2019 ◽  
Vol 20 (2) ◽  
pp. 147-154
Author(s):  
Mikhail V. Lapin ◽  
Andrey O. Grinin ◽  
Kirill V. Shkarin ◽  
Kambiz Soury

Article is dedicated to liquid flow measuring by acoustic flow meters. Manufacturers establish the allowable measurement range (nominal), within which the measurement error is minimal, that’s why their measuring span is limited, and the measurement error when operating in off-design modes is unacceptable. The basic task of this research is to expand the range of flow measurements of acoustic liquid meters. V.A. Fafurin and M.K. Galeev in their work “Calculation of the correction coefficient of the ultrasonic flow meter” have already considered the problem of measuring the flow rate of acoustic devices. In their study was presented a method for calculating the correction coefficient, which depended on the flow regime in the pipe. But this technology is applicable for change-less flow regime pipes. In this article, the authors propose to use a coefficient that has a functional dependence on the magnitude of the flow, obtained empirically. The article describes the stages of the study: the method of calibration of the device, methods of analysis and processing of verification data by PC, the algorithm of measurement system implementation in power engineering equipment, system performance check. The system presented in the article allows to expand the range. The proposed model will be useful for enterprises.


Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 500-501
Author(s):  
S Ross ◽  
D P Cochran

Methods by which patients can artificially produce raised peak flow measurements have been described. We recently observed a patient manipulating the peak flow meter in a way that had not been described before. A study was therefore undertaken to determine if this technique could repeatedly produce clinically significant changes in peak flow readings. Fifteen adults, using a mini-Wright peak flow meter, made five measurements using the correct technique followed by five manipulated measurements under observation. Significant increases in peak flow measurements were observed in 14 of the 15 subjects. The mean increase in peak flow rate using the incorrect technique was 56% (range –4% to 86%). Clinicians should be aware that patients might employ this technique to manipulate measurements which could have consequences for management.


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