Real-time Flow Rate Research Articles

Optical spectroscopic based in-line iodine flow measurement system – an application to COIL

Precision measurement of iodine concentration is an essential diagnostic tool in the development and optimization of chemical oxygen-iodine laser (COIL) system. A simple technique based on absorption spectroscopy has been developed and the absorption cell assembly was interfaced with the data acquisition and control system (DACS) for monitoring the iodine flow rate in real time. The assembly is being used in our 500 W COIL system and more than 600 power runs have been given.

A DISCIPLINED FLOW ESTIMATION ALGORITHM IN THE DEBAKEY VAD?? SYSTEM

PURPOSE A dual-channel flow probe and meter are used to continuously measure real-time blood flow rate in the DeBakey VAD®. The system provides a true, calibrated, and independent metric of blood flow while consuming approximately 0.5 Watts. Power reductions, however, may be obtained by deriving flow directly from intrinsic pump signals. The algorithm's accuracy is ensured by periodically verifying its output to the existing flow meter's output using duty cycle control. METHODS: A primary data table containing the DeBakey VAD®'s flow versus power and speed information was stored into a low-power microntroller. The microcontroller was programmed to sample the pump's analog power and speed signals and, via the primary data table, output the corresponding flow value for display and pump control purposes. The real-time flow meter was periodically energized and its output compared to the derived value. The duty cycle used to control the real-time flow meter was proportional to the difference between the actual measured flow and derived flow values. Additionally, a secondary data table containing actual flow information was stored and used to prove that the algorithm performed correctly over the course of its use. CONCLUSION: A flow estimation algorithm whose accuracy is periodically verified against an independent metric has been realized for use with the DeBakey VADB. This hybrid approach allowed the algorithm to be tested in a safe and controlled manner and reduced power consumption by more than a magnitude while maintaining the precision of the existing real-time acoustic flow meter.

The control and data acquisition system of a laser in-vessel viewing system

This paper presents the dedicated control and data acquisition system (CADAS) of a new laser in-vessel viewing system that has been developed for inspection purposes in fusion experiments. CADAS is based on a MC68060 microprocessor and on-site developed VME instrumentation. Its main aims are to simultaneously control the laser alignment system as well as the laser beam deflection for in-vessel scanning, acquire a high-resolution image and support real-time data flow rates up to 2 Mbyte/s from the acquisition modules to the hard disk and network. The hardware (modules for control and alignment acquisition, scanning acquisition and monitoring) as well as the three levels of software are described.

MASS FLOW MEASUREMENT OF SEED COTTON

Systems obtaining real-time mass flow data were developed to support cotton gin automation. Theexperimental systems used the attenuation of optical and ultrasonic signals, inertia, and air pressure differences causedby changes in potential energy. A conveyor belt standard indicated real-time accuracy while a truck scale standardverified accuracy integrated over time. Conveying air velocity pressure and vertical pipe air pressure differential mostaccurately reflected mass flow. Their estimate of mass flow rate in real time was within 10% of the belt scale. Bothsystems are inexpensive to make and easy to add to an existing cotton gin.

Rapid volume flow rate estimation using transverse colour Doppler imaging

A system is described in which the volume flow rate of blood in a vessel is determined using transverse colour Doppler ultrasound imaging. The system measures rapidly the two-dimensional velocity profile of blood flowing through a vessel. By integration of the measured velocity profiles the volume flow rate of blood in the vessel is obtained. The Doppler angle is obtained from the included angle between two imaging planes, and their respective average measured flows. This technique yields instantaneous and average flow rate in real time, and permits long flow recordings to be made and stored digitally. The error is less than 5% over a 8:1 flow rate range.