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The flow rate of water, and the accuracy used to measure it, is important to know. Numerous international and national standards exist, defining the conditions for flow measurement. However, the needed “standardized flow conditions” are often impossible to satisfy in field and they can be used just as guidance. This paper presents four cases with such non-standard conditions, where the author had to perform the flow rate measurement. For each case the approach used is explained, the results obtained are given and the achieved accuracy is assessed. All measurements were performed using electromagnetic (EM) velocity measurement probes, specifically designed to suit local conditions. Parallel to direct velocity measurement, CFD (Computational Fluid Dynamics) was used to analyse the flow conditions and get better insight into the flow field, with an idea to extract the data from modelled flow field in order to perform the flow meter calibration. Throughout the presented cases, which cover last two decades, clear developments of both hardware and knowledge can be seen.

Merenje protoka u kolektorima sa otvorenim tokom, kao i kanalizacionim sistemima predstavlja izazov jer ne postoji jedna najbolja metoda, već je neophodno dobro poznavati radne uslove i shodno njima izabrati optimalnu mernu metodu. U ovom radu je prikazana elektromagnetna (EM) metoda koja koristi ravne sonde, prilagođene ugradnji u kanalizacione sisteme. Ravne EM sonde su robusne, mogu da mere izuzetno male brzine (pri usporu) kao i velike brzine tokom kišnih epizoda, mogu da rade sa jako malim dubinama a i otporne su na nanos i prljavštinu koja može da se na njima nataloži. Kod većih proticajnih profila je moguće više ravnih EM sondi povezati u jedan integrisani sistem, čime se dobija bolja prostorna integracija brzina a ukupna cena sistema ostaje relativno mala. U radu su dati rezultati detaljnih ispitivanja sondi sprovedenih na Građevinskom fakultetu: snimanja 3D magnetnog polja radi definisanja kontrolne zapremine i težinskog vektora u realnim radnim uslovima, rad ravnih EM sondi pod nanosom i korekciju merenja u takvim uslovima, kao i metodologija primene CFD radi analize uticaja realnih uslova tečenja. Na kraju rada su dati i primeri upotrebe ravnih EM sondi na nekoliko sistema., Flow measurement in trunks with open flow and in sewer systems is still a challenge: there is no one “the best” method which can solve all requests, but user has to optimize the selection of equipment to fulfill the existing flow and working conditions. One of the possibilities is to use the flat electromagnetic (EM) probes, presented in this paper. Flat EM probe is designed to suit the needs of sewer systems, i.e. they are robust, can operate with low velocities of few cm/s and at the same time can measure high velocities during heavy storms, can work with shallow water and even will operate if covered with sludge and sediments of reasonable height. In large flow profiles, user can easily integrate more flat EM probes into one system, improving the spatial integration of measured velocities and at the same time keeping the low overall costs. Results of laboratory investigation at Faculty of Civil Engineering in Belgrade are presented in the paper: mapping of 3D magnetic field to delineate the control volume and calculate the weighting function in real conditions, operation of probe under the heavy sediment load of different height and usage of CFD to analyze the influence of real flow filed. Few examples of flat EM probe applications are presented at the end of the paper.

type:Journal Article, A radiative deuteron–proton capture experiment was carried out at KVI using polarized-deuteron beams at incident energies of 55, 66.5, and 90 MeV/nucleon. Vector and tensor-analyzing powers were obtained for a large angular range. The results are interpreted with the help of Faddeev calculations, which are based on modern two- and three-nucleon potentials. Our data are described well by the calculations, and disagree significantly with the observed tensor anomaly at RCNP., source:http://www.sciencedirect.com/science/article/pii/S0370269305006003

Benchmark and validation studies are presented that quantify the accuracy of computational models. An important factor in these studies is the ability to compare simulated impedance results with experimental data. In a majority of differential benchmark studies the data acquisition is handled by a commercial eddy current instrument which allow for only a relative comparison of the data. In this study a novel data acquisition system allows for the collection of impedance data for differential probes. Details about the data collection, experimental procedure, model construction, and data comparison will be presented., Published in the proceedings of Review of Progress in Quantitative Nondestructive Evaluation, QNDE 2013, in Baltimore, MD on 21-26 Jul 2013. Prepared in collaboration with University of Dayton Research Institute and Computational Tools. The original document contains color images.

The majority of data presented in this work is for a helicon plasma discharge driven at 13.56 MHz, 500 Watts input power, 900 Gauss applied magnetic field, 10 mTorr neutral Argon gas, and cylindrical plasma of 5 cm diameter approximately 50 cm long. High frequency magnetic induction probes were developed to measure helicon wave propagation using a new technique for frequency calibration through an impedance analyzer; up to 100 MHz. This work demonstrates magnetic field measurements in high frequency plasma are greatly simplified through this new frequency characterization method. Line-lengths and transmission-cable-types are readily identified as diagnostic limiting factors. The magnetic probe design enables the first 3-dimensional imaging of plasma waves through detailed radial and axial measurements. Strong agreement is obtained between the measured b(r), b(theta), and b(z) radial profiles with the numerical solutions of helicon waves when a non-uniform radial density profile is considered. The axial helicon wavelength predicted by the non-uniform radial density theory also agrees with the measured wavelength when the full three dimensional wave is accurately analyzed. In some cases, the differences between the three dimensional wavelength and the numerically solved values are less than 30%. This is in contrast to the two dimensional wavelengths which can differ from the numerical values by greater than 100%. We show a complete visual representation of helicon waves through 3-d imaging which provides significantly more accurate analysis of the helicon wavelength., Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Nuclear Engineering, University of Illinois at Urbana-Champaign.

In this paper, a contactless measuring system for the determination of the S-parameters of planar circuits is presented. With a contactless measuring system it is possible to characterise a device-under-test (DUT) embedded in a planar circuit environment without cutting the planar transmission lines connecting the DUT. The technique utilizes four identical capacitive probes in conjunction with a vector network analyser (VNA). For the usage of electromagnetic probes compared to other coupling techniques like the electro-optic probing, there is no need for expensive and complex equipment in addition to the typical equipment of a common microwave laboratory. The S-parameters are determined accurately using conventional calibration methods. A simple analytical model for the representation of the basic characteristics is developed. Furthermore, the influences on the S-parameters as a result of a variation in the coupling are presented. With the knowledge of the system characteristics, an accurate contactless measurement system is set up. The comparison between conventional and contactless measurements in a frequency range of 1-20 GHz shows a very good agreement with a phase error smaller than 1°.

The QCD sum rule approach to in-medium modifications of the omega meson in nuclear matter is reviewed with emphasis of its relation to 4-quark condensates and chiral symmetry restoration. Possible implications of the CB-TAPS experiment for the reaction gamma A -> A' omega (-> pi0 gamma) are sketched and the particularly important role of di-electron probes, accessible with HADES, is highlighted. A brief update of a parametrization of the previous dilepton and photon probes from CERES and WA98 of heavy-ion collisions at CERN-SPS energies is presented.

The QCD sum rule approach to in-medium modifications of the omega meson in nuclear matter is reviewed with emphasis of its relation to 4-quark condensates and chiral symmetry restoration. Possible implications of the CB-TAPS experiment for the reaction gamma A -> A' omega (-> pi0 gamma) are sketched and the particularly important role of di-electron probes, accessible with HADES, is highlighted. A brief update of a parametrization of the previous dilepton and photon probes from CERES and WA98 of heavy-ion collisions at CERN-SPS energies is presented.

This paper introduces a method for extracting information from single channel recordings of electromagnetic (EM) brain signals. In a dynamical embedding framework, the measured electroencephalogram (EEC) and magnetoencephalogram (MEC) signals are assumed generated by the non-linear interaction of a few degrees of freedom. In a three-step process, first an appropriate embedding matrix is constructed out of a series of delay vectors from the measured signal. Then independent component analysis (ICA) is performed on the embedding matrix to decompose the single channel recording into its underlying independent components (ICs). The ICs are treated as a convenient expansion basis and subjective methods are then used to identify components of interest relevant to the application. These ICs are then projected back onto the measurement space in isolation. The method has been applied to single channels of both EEC and MEC recordings and is shown to isolate, amongst others: i) artifactual components such as ocular, electrocardiographic and electrode artifact, ii) seizure components in epileptic EEC recordings and iii) theta band, tumour related, activity in MEC recordings., Papers from 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, October 25-28, 2001, held in Istanbul, Turkey. See also ADM001351 for entire conference on cd-rom.

This report documents field evaluations of the capabilities of GEM-1, an electromagnetic subsurface surveying instrument. GEM-1 was developed under the Small Business Innovative Research (SBIR) program as a tool for the expedient location of lost underground fuel storage tanks. GEM-1's characteristics allow its application to a variety of nonintrusive subsurface exploration applications. Evaluations conducted by USACERL included successful location and mapping of known and unknown underground storage tanks, pipes, a leach field, and a retired landfill. Searches for small buried pipes and small surface placed ordnance were relatively unsuccessful, however, because the geometry and sensitivity of GEM-1 were designed for significantly larger targets. Many more applications of electromagnetic subsurface exploration will likely become common with the availability of GEM-300, a commercially produced device based on the concepts and capabilities tested in this program.

The major focus of this project was on the construction and testing of high pressure, high resolution multinuclear NMR probe with unique performance features which permits measurements up to 10 kbar. Several experimental NMR studies of confined fluids of methylcyclohexane; perfluoromethylcyclohexane; ethanol; 2,2,2-trifluoroethanol; propionic acid and pentafluoropropionic acid were finished. These studies provided information on the effect of fluorination on the dynamic behavior of selected model liquids confined to porous silica glasses. In addition, natural abundance 31C NMR relaxation study of the dynamics of polyfluorinated alkyl ether lubricant fluids was carried out.

Geophysical surveys were conducted at solid waste management units (SWMU's) 14100 and 17104, Naval Surface Warfare Center, Crane Division, Crane, Indiana. The purpose of the surveys was (1) to detect and delineate the locations of lithium batteries reported to be buried in SWMU 14100 and (2) to detect and delineate the locations of electrical capacitors reported to be buried at SWMU 17104. The locations of these objects are needed so they can be excavated for removal to a permanent treatment or disposal site. Electromagnetic, magnetic, and ground penetrating radar survey methods were used at SWMU 14100. All the surveys performed at SWMU 14100 indicate an anomalous zone inside a rectangular area approximately 50 ft wide and 60 ft long. The size, shape, and intensity of the anomalies are consistent with the size, composition, and estimated depth of burial of the lithium batteries. The location of the anomalous area lies within an area defined by three metal poles. SWMU 17104 was surveyed using a cesium magnetometer. The results of the survey indicate four distinct, relatively small (about 2 to 3-ft diameter) anomalies and one large, 2O ft diameter, anomaly. The size of the four small anomalies are consistent with the size and depth of burial of the capacitors. (AN)

A velocimeter for measuring the velocity field characteristics of a conductive fluid moving over a surface is provided. A magnet has a central axis that is aligned with a direction of fluid movement of interest such that a plurality of magnetic flux lines extend generally normal from the surface. A plurality of electrode pairs provide electrical output signals that are proportional to variations in the magnetic flux lines as the conductive fluid flows therethrough in accordance with Lorentz forces. Each electrode pair is disposed symmetrically about the central axis of the magnet. The plurality of electrodes are mounted in a fixed relation with the magnet. The electrical output signals from the electrode pairs are processed and displayed as the velocity field characteristics of the fluid in the direction of interest.

The Multi-Scale Profiler (MSP), a freely falling dropsonde, has been used over the last 12 years to resolve oceanic shear variance at vertical scales from a few hundred meters down to nearly a centimeter. Because MSP yielded the first complete oceanic shear spectra., it is important to document the methods by which they were produced. Large scales are measured by an electromagnetic current meter (ECM), microscales by airfoil probes, and intermediate scales by an acoustic current meter (ACM). The ACM detects velocity relative to the instrument, so the platform motion must be known to determine the water velocity. Primarily, the ACM measurements are affected by tilt oscillations and by the gross (point-mass) motion of the vehicle; the former is inferred from accelerometer data, and the latter is constructed from a model of the vehicle's response to oceanic shear. Horizontal forcing on the array of drag brushes and turning blades at the tall complicates the response by causing MSP to react strongly to fluctuations with scales near the instruments length of 4.3 m. We examine the effects of this response on spectra of the ACM measurements, noting particularly a deep notch near 0.2 cpm (cycles per meter). To account for such spectral features, the model of Hayes et al. for the TOPS dropsonde was modified so that it correctly parameterized our large tail force. We discuss the dynamics, data processing, and model formulation relevant to production of oceanic velocity profiles from the ACM data,and present analytic transfer functions-derived from Fourier transforms of the model equations-which guide selection of optimal values for the model parameters., Sponsored in part by Grant ONR-N00014-94-I-0079 and Grant URI/UW-N00014-86-K-0690.

A flexible core eddy current probe is disclosed for testing of curved or irregular surfaces. The core is comprised of a flexible binder loaded with a powdered magnetic material and then formed into a specific flexible core shape continuously adaptable to irregular or curved surfaces. The flexible core probe has specific application to carbon fiber reinforced composite components having contoured surfaces.

It is theoretically possible to detect plastic fragment in the human body. A lateral wave locator will need to operate, in general, in the fleshy parts of the body, since large bone reflections are possible. These parts include the abdomen, buttocks, and fleshy parts of the leg and hips. With the help of an experimental probe development set-up, many of the practical considerations for realization have been identified. Considerations include a nulling circuit for canceling out the direct wave and shielding to reduce noise. Details in the design of the probe are now evident: (1) the desired mode of operation is C.W. with an operating frequency of 10 GHz; (2) a thin layer of a polyfoam type material is needed to press the dipoles against the body; (3) tuning is required to resonate the dipoles; (4) the dipoles must be collinear; and (5) in many cases bone can be differentiated from fragments through the polarization response. As a rule of thumb, it is possible to detect fragments in the range from millimeters to centimeters at depths up to 10 cm. The maximum depth for detection depends on fragment size. Based on the present limited experimental probe design work, many of the practical problems have been identified.

The submarine propulsor and maneuvering technology program will provide a better understanding of the forces, moments, and acoustic behavior characterizing an underwater vehicle during a maneuver. Propulsor performance during the maneuver is particularly important, since it is a primary determinant of vehicle trajectory. Hydrodynamic measurements in this program will improve the reliability of and confidence in current analytical model predictions. For some maneuvers, flow predictions have not previously been possible. Flow phenomena isolated and defined by program measurements axial and tangential inflow velocities and propulsor forces should provide the understanding needed to build new analytical models. In this report, the capability of the propulsor inflow velocity measuring system for a self-propelled model is projected. This system will provide the first measurements of the propulsor inflow field during maneuvering to support development of computational models of propulsor performance. The proposed measuring system uses seven miniature laser-Doppler- velocimeter probes. Temporal and spatial resolution that can be obtained with the system are estimated relative to flow time scales. Operation in both scanned and non-scanned modes is recommended. Measurement of the propulsor inflow field will be effectively instantaneous relative to the maneuvering time scale. Keywords: Laser Doppler velocimeters; Time scales; Underwater maneuvering.

Modern electromagnetic radiation testing techniques require accurately calibrated field probes that can operate over a wide range of frequencies, without adjustments. This requirement is an outgrowth of the use of wideband radio frequency amplifiers and computer-controlled swept frequency generators. The computer can control the field strength accurately only if accurate sensor information is continuously available. One type of sensor that fulfills this requirement is the b dot probe. The b dot probe is a matched 50- ohm multigap loop which measures db/dt according to faraday's law. To assure the accuracy of the probes, a calibration against the National Bureau of Standards' standard dipoles is required. From this calibration data a polynomial is developed which when multiplied times the output of the probe in milliwatts will give the actual field strengths. The output of a digital power meter is fed into the computer which applies the calibration polynomial and allows a real- time electromagnetic field leveling to be accomplished. This technique is applicable any time broadband electromagnetic leveled field is required. This study also outlines the design and construction of a single-ended 50-ohm b dot probe, as well as the calibration and development of the required calibration polynomial for computer use.

The purpose of this report is to describe a relatively fast computer algorithm to estimate plasma parameters from measured ion current flow to a planar ion sensor as a function of applied potential. It was developed for the preliminary processing of data obtained by the retarding potential analyzer (RPA) flown by the Air Force Geophysics Laboratory on board the DMSP satellites and on the HILAT satellite. For a sparse set of data points, such as the HILAT data, this method estimates the drift velocity with less uncertainty than it estimates temperature.

The in line four point probe, commonly used for measuring the sheet resistance in a conductor, cannot measure the anisotropic ferromagnetic magnetoresistance. However, the addition of two contact points that are not collinear with the current contacts give the probe the ability to non-destructively measure the anistropic magnetoresistance. Keywords: Magnetoresistance; Anisotropic; Thin-Film; Permalloy; Four Point Probe; Anisotropic Resistance.

The development and function of a small, diver-held, easy-to-use electrical conductivity probe developed to support Navy shallow water environmental surveys is described. The probe was designed to measure directly seafloor conductivity or resistivity, temperature and depth of sensor embedment. Geotechnical/geoacoustic properties derived indirectly from the resistivity probe data included sediment porosity, wet bulk density and sediment property variability.

The objective of this research program is to develop the theoretical models, design methodology, and technology needed for optimum application of near field electromagnetic sensor arrays in nondestructive evaluation (NDE) and robot control. To aid in understanding how best to analyze and control the spatial-frequency content in the field configuration generated by an array, most of this year's effort focused on obtaining experimental measurements of the relative spatial distributions defined by the responses of inductive eddy current reflection probes to surface steps and surface breaking rectangular slots in aluminum plates. In particular, a commercial reflection probe (Nortec SPO-2065) and an SRI-constructed, five coil, air core reflection probe have been used to interrogate such surface discontinuities. The data obtained using the five coil probe compare favorably with the results of the developed theory.

Novel high resolutions electromagnetic wave techniques have been used in the optical, infrared and far infrared spectral regions to explore the electronic states at metal dielectric interfaces. Because infrared surface plasmons on metal surfaces propagate for many wavelengths, a measurement of the transmission of these surface excitations has proven to be a sensitive probe of the surface itself. Both broadband and single frequency generation techniques have been developed. Reconstructed surfaces as well as surfaces covered with a chemisorbed atomic monolayer or a thin dielectric or molecular film have been investigated with these new methods. Keywords: Electromagnetic; Electronic; Broadband.

The purpose of the work summarized in this report is to identify and develop a cost effective, reliable procedure for identifying potential blade failures in time to prevent the actual occurrence. The procedure is developed for application to an Allis-Chalmers ten-stage, axial flow compressor, Model VA 1310. The approach followed in conducting this study included a review of the current techniques used to insure blade integrity, a review of other approaches as described in literature for verifying the condition of compressor blades and, finally, development of a technique suitable for use with the VA 1310 compressor.

Experiments directly measuring the plasma conductivity have been done on pulsed, high voltage discharges. The channel conductivity was measured by a two coil RF-probe and verified using conventional collecting Langmuir probes. The conductivity measured by these two methods agrees very well. These experiments also demonstrate the potential for the two coil RF-probe to yield useful data in intense electron beam environments.

A self contained electrically floating spherical electric field probe has been developed use in volume regions where spatial field variation occurs on a length scale larger than the sphere diameter. In plasma sheath, the sphere floats to the local plasma potential, minimizing field perturbation, and provides a value of field magnitude found from the Laplacian spherical harmonic field solution. The sphere is also capable of monitoring the amount of charge collected on its own surface--a quantity that can in principle be used to infer properties of the ambient plasma. The 15 cm battery operated aluminum sphere contains six miniature 800 Hz field mill sensors, a synchronous detection data acquisition system and A/D converter, and 50 MHz digital fm transmitter. Data is sent at 1200 BAUD to a nearby receiver and computer for processing in real time. Fields as low as 50 V/m can be detected with a sampling time of about 1 second. At present the probe works well in air and vacuum, but has been only partially successful plasma. Keywords: Electric field measurements; Plasma; Sheath; Sensors; Probe; Surface; Charge; Sphere; Projectile; Floating.

This study resulted in the development of a procurement specification for single-coil, absolute eddy current probes (shielded and nonshielded) which are used by the USAF with the Hocking UH-B (or equivalent) instruments for inspection of aluminum airframe structures. The specification was necessary because the USAF currently has no adequate means of assuring the quality of eddy current probe performance. The specification establishes minimum performance requirements and associated test methods for determining performance. It also establishes a standard nomenclature for the salient features of probes and a standard probe numbering system that allows the basic characteristics of the probes to be identified on the probe in a uniform manner. A simplified field test procedure for these probes which incorporates a subset of the tests in the specification was also developed. To establish performance requirements for the specification, the major parameters determining probe performance were defined. Acceptance limits for these parameters were guided by measurements from 30 shielded and 30 nonshielded probes. The probes were obtained from USAF inventory at numerous Air Force bases and were representative of proves in current use. The acceptance limits were set to reject probes with poor performance and not reject a high percentage of probes with typical performance. Keywords: Flaw detection probe standards; Electrical measurement test methods.

Superconductive quantum interference devices (SQUIDS) offer new technology for locating materials flaws electromagnetically that promises to increase sensitivity, depth of magnetic flux enables use of microscopic pickup loops in a gradiometer configuration to give high resolution. A cryogenic umbilical connects pickup loops to a remote cryostat housing SQUID sensors to ease scanning. A pair of drive coils a few millimeters in radius that encircle pickup loops forming a coplanar gradiometer 1 mm or less in radius comprise a superconductive microprobe. It provides a depth of field of several millimeters to a 0.1 mm flaw in an aluminum plate, when operating with a drive current a 1 A oscillating at a frequency of 1kHz. Its field of view ranges to several millimeters, for flaws a few millimeters deep, and its horizontal resolution is 1 mm or so, for flaw depths out to its depth of field. An array of microprobes form receptors much like rods in the retina of a magnetic eye. The eye leads to an electromagnetic microscope for imaging internal flaws in aluminum plates. It gives multiple images that enable resolving depth of a 0.1 mm flaw to a few tenths of a millimeter with a horizontal resolution of one millimeter or so. (kr)