摘要:
A magnetic resonance based apparatus capable of measuring, without using time-of-flight measurements, flow regimes of multi-phase fluids in a pipe, comprises a magnetic resonance module through which the fluid phases flow, wherein the magnetic resonance module includes a radiofrequency coil for transmitting and detecting a signal and means for generating inside the module a homogenous constant magnetic field Bx that is thermally compensated and a transverse magnetic field gradient Gx that is superposed on Bx; and at least one pre-polarization module through which the fluid phases flow before entering the magnetic resonance module
摘要:
An apparatus and a method is provided based on the Magnetic Resonance techniques to analyze and measure a uni- and/or a bi-directional flow regime of multiphase fluids in a transport and production conduct, in real time and flow-rates, based on a magnetic resonance analytical module, two magnetic prepolarization modules of variable effective length and a control computer of data acquisition and transfer, all associated to each other.
摘要:
In an imaging method for spectroscopy of nuclear quadrupole resonances (NQR) with solid samples to which an RF field having a pulse duration t.sub.p with a base amplitude B.sub.10 constant over the sample length for magnetic excitation of NQR with resonance frequencies .omega. and with magnetic moments coupled to the nuclear quadrupole moments is applied and the NQR signal emitting from the sample is time-depentently detected, the RF field is superimposed by a position-dependent field contribution corresponding to a constant gradient B.sub.1.sup.x which yields together with the constant RF field a position-dependent RF field B.sub.1 (x), for each resonance frequency contained in the detected NQR signal the amplitude including its sign is determined, the measurements are carried out at different flip angles.sqroot.3.multidot..gamma..multidot.B.sub.1 (x).multidot.t.sub.p of the excited magnetic moment, the amplitudes including their signs which depend on the flip angle are subjected to a Fourier transformation and finally therefrom the x dependent density distribution of the observed nuclei is reconstructed. The method does without applying of an external B.sub.0 field, so that it can be carried out with a compacter measuring apparatus, in which the sample can also be situated partly outside. Effects of the Zeeman splitting do not have to be taken into consideration.
摘要:
A method for measuring flow rate of at least one fluid in a multi-phase fluid comprises: providing a magnetic resonance module through which the fluid phases flow and at least one pre-polarization module of variable effective length upstream of the magnetic resonance module; and conducting, a measurement by: i) setting the pre-polarization module to have a first effective length, ii) applying a RF pulse sequence to the fluid, in the magnetic resonance module, iii) determining the intensity of a pre-determined number of spin echoes produced by the RF pulse sequence, iv) determining a line approximating the attenuation of the intensity during the RF sequence, v) determining slope and y-intercept of the line, vi) determining the ratio of the slope and intercept, vii) applying a calibration between the slope:intercept ratio and multi-phase flow rate so as to determine the flow velocity of the fluid in the multi-phase fluid.
摘要:
The present invention contributes to the resolution of the problem of detecting, for example, plastic explosives, which are not easily detected by conventional inspection techniques, as those based on X-ray apparatuses; or those using more sophisticated means from traces of explosive material which may remain, “contaminating” the external surface of luggage. As regards the first technique, the invention has an additional advantage in that it is fully automatic, that is, it is independent from the operator's ability to interpret low contrast images. As regards the second technology, the main advantage of the present invention consists of its speed and safety when inspecting luggage.
摘要:
A sensor assembly for the detection of substances by means of nuclear quadrupolar resonance (NQR) and in the presence of environmental interference. The sensor assembly has a transmitter Tx which comprises excitation means which generate excitation signals and a switch connected at the outlet of the Transmitter. A first phase-shifted signal divider/adder is connected to the outlet of the Tx/Rx switch. First and second sensor elements are connected to the respective outlets of the first phase-shifted signal divider/adder. First and second coupling circuits, preferably in common, are connected to the outlet of the first and second sensor elements, respectively. First and second amplifiers are connected to the outlets of the first and second coupling circuits, respectively. First and second bandpass filters are connected to the outlets of the first and second amplifiers, respectively. A second phase-shifted signal divider/adder is connected to the outlets of the first and second bandpass filters, respectively. A receiver Rx is connected to the inlet of the second phase-shifted signal divider/adder. The method associated to the sensor assembly is also disclosed.
摘要:
A method for determining individual component flow-rates in a multi-phase fluid flowing in a pipe comprises the steps of: a) flowing the fluid through a magnetic resonance based apparatus comprising a magnetic resonance module and at least one pre-polarization module through which the fluid phases flow before entering the magnetic resonance module, wherein said pre-polarization module comprises a plurality of cylindrical segments that can be selectively combined so as to modify the effective length of the pre-polarization module, b) selectively using the prepolarization module to polarize a component in a volume of the fluid, c) applying a selective excitation to said fluid volume, d) using a signal resulting from said excitation to obtain a velocity measurement for said component, and e) repeating steps b)-d) until velocity measurements for a desired number of components have been obtained.
摘要:
A method for measuring flow rate of at least one fluid in a multi-phase fluid comprises: providing a magnetic resonance module through which the fluid phases flow and at least one pre-polarization module of variable effective length upstream of the magnetic resonance module; and conducting a measurement by: i) setting the pre-polarization module to have a first effective length, ii) applying a RF pulse sequence to the fluid in the magnetic resonance module, iii) determining the intensity of a pre-determined number of spin echoes produced by the RF pulse sequence, iv) determining a line approximating the attenuation of the intensity during the RF sequence, v) determining slope and y-intercept of the line, vi) determining the ratio of the slope and intercept, vii) applying a calibration between the slope:intercept ratio and multi-phase flow rate so as to determine the flow velocity of the fluid in the multi-phase fluid.
摘要:
A device for the real time direct measuring of the proportion and flow-rate of the different components which conform a multi-component complex fluid, which device comprises a set of mutually associated control computer, derivation device and electronic measuring device, the derivation device being connected to a plurality of sensor assemblies through which said multi-component complex fluid circulates.
摘要:
A magnetic resonance based apparatus capable of measuring, without using time-of-flight measurements, flow regimes of multi-phase fluids in a pipe, comprises a magnetic resonance module through which the fluid phases flow, wherein the magnetic resonance module includes a radiofrequency coil for transmitting and detecting a signal and means for generating inside the module a homogenous constant magnetic field Bx that is thermally compensated and a transverse magnetic field gradient Gx that is superposed on Bx; and at least one pre-polarization module through which the fluid phases flow before entering the magnetic resonance module.