Southwest Research Institute

Gas Research Institute

William L Rollwitz

James Derwin King

Armando De Los Santos

George A Matzkanin

William Dean Perry

Robert Wayne Burrahm

Colin I Nicholls

Erroll S Riewerts

Phillip A Hornung

James K Davis

A telemetric measuring device for measuring physical conditions of machinery having a periodically moving part. The device generates its own power with power generator that uses the periodic motion of the machinery to move a reciprocator slug inside a coil, and thereby opening and closing a magnetic circuit and generating a continuous alternating current. This current powers a transmitter that receives output from a multi-channel switch for a number of sensors. The transmitter delivers a radio frequency signal, whose frequency is a function of the condition being measured.

Telemetric measuring device with high power generation

A method of using a transient NMR response signal to determine physical properties of gases, specifically calorific content and compressibility, while the gas is in-line. The amplitude of the free induction decay signal, as well as relaxation time constants, are used to identify components of a gas mixture and to determine relative composition. This data is then used to calculate calorific value and compressibility as a function of the hydrogen content of components of the gas rather than as a function of the total hydrogen content of the gas.

Hydrocarbon gas measurements using nuclear magnetic resonance

In the preferred and illustrated embodiments hereof, a method and apparatus for conducting NMR moisture measurements is set forth. In various forms, hydrogen transient NMR signal peak amplitude values indicative of total hydrogen concentration of the tested material space. The hydrogen concentration is converted by a constant into water concentration. In one embodiment, a comparison is made between the NMR peak voltage of the unknown material and the NMR peak voltage from a standard sample having a specified water content to obtain a calibration for determining moisture content as a weight percentage in the tested specimen. If the densities of the two samples vary, the weights of each are necessary for accurate measurements. An alternative procedure involves determining moisture and material from the hydrogen in the water and in the material itself. In this procedure, the spin-spin relaxation T.sub.2 for the moisture is preferably more than three times longer than the T.sub.2 for the hydrogen in the solid or substrate hygroscopic material. Subsequently, two separate measurements can be obtained at separate times and their proportion is related to the percent water. An alternate procedure is used when the T.sub.2 of the water varies as a function of the percentage of water. In that instance, the values proportional to the total hydrogen in the sample and to the hydrogen in the water must be obtained at the same time so that the ratio is proportional to the percent water independent of the variations in T.sub.2. In the last two procedures, weight measurement is not required.

NMR moisture measurements

A method and apparatus are set forth for measuring flow velocity of an element of interest in a compound within a pipe. In the preferred and illustrated embodiment, a static magnetic field is imposed on the flowing material of interest. Preferably, a uniform field of finite width is imposed. There is a first coil around the path for imposing an RF magnetic field at right angles to the static magnetic field. There is a relationship between the flowing material including the element, frequency of the RF field and static magnetic field intensity which aligns nuclei or electrons of the element. There is a second (detection) coil spaced downstream from the first coil, the second coil also being around the pipe. By turning the first coil off or on, the NMR or EMR signal observed at the second coil can be made to change abruptly as the 'tagged' element flows to the second coil. By measuring the time of travel of the element of interest evidenced by the second coil signal, the flow velocity can be measured. An alternate embodiment utilizes a magnetic field gradient at the coils to narrow the coil field dimensions.

Method and apparatus for nuclear magnetic resonant measurement of flow

A method and apparatus for testing for cancer cells in the human breast is set forth. In the preferred and illustrated embodiment, a pendulant breast exposed to a magnetic field is tested by nuclear magnetic resonant (NMR). The magnetic field is varied to provide the requisite field intensity in selected segmented sections of the pendulant breast within the field. The field intensity is varied to thereby observe all of the breast extending toward the thorax cavity, obtaining test data from section after section aggregating test data from the entire breast within the pole pieces of the magnet and sufficiently therebeyond to obtain full interrogation. The NMR response focuses on hydrogen nuclei in the water in the breast region, determines the voltage proportional to the density of hydrogen nuclei and the binding of the water described by the relaxation times T.sub.1 and T.sub.2 for each binding level for water. The data so obtained in sequence is examined. Difference values from sequentially obtained signals are evaluated, yielding a plot of different signals as a function of breast length, thereby yielding abnormalities. Such abnormalities are shown in the difference signal from NMR interrogation as a result the concentration and relaxation time (T.sub.1 and T.sub.2) changes in tumo

Method for in-vivo NMR measurements in the human breast to screen for

A flow meter apparatus and method for measuring the flow, composition and heat content of coal is set forth. In the preferred and illustrated embodiment, the free or unpaired electron population of flowing coal is measured by electron magnetic resonance (EMR); the hydrogen nucleii population is measured by nuclear magnetic resonance (NMR). By calibration utilizing a standard specimen for a given type of coal, a profile for various types of coal can be obtained wherein measurement data is converted into an indication of the heat content typically measured in BTU per pound. This enables provision of a volumetric flow meter, a flow meter indicating flow in calorie content. This device enables integration to provide total heat content flow. Other variables describing the coal can be obtained.

Method and apparatus for coal analysis and flow measurement

This method and apparatus are directed to baggage inspection, and more particularly, baggage inspection to locate explosives. In the preferred and illustrated embodiment, a conveyor system is utilized to transport a bag past a first magnet to achieve an initial nuclear magnetic resonance (NMR) polarization of a selected element. The element in the preferred embodiment is hydrogen, it being noted that hydrogen in explosives has a long T.sub.1 and a short T.sub.2. The first magnet provides an initial polarization. The bag continues on the conveyor belt past a second magnet. The second magnet provides the measurement field intensity and a coil contains an interacting RF forming the interrogation pulses. Echos are received. In the preferred embodiment, first and subsequent second echos are received and stored. The two signals are subtracted from one another to a null. The NMR response of elemental hydrogen in compounds typified by explosives (having a long T.sub.1 and short T.sub.2) is accented by subtraction of the two stored signals to form a response indicative of explosive materials. The apparatus includes means for adjusting the magnetic field to accommodate distortions for metal in the baggage.

Baggage inspection apparatus and method for determining presences of

A method and apparatus for enhanced nuclear magnetic resonance (NMR) discrimination and detection is disclosed. In the preferred embodiment, a sample which has a first atomic element is placed in a magnetic field of a first intensity. A reaction between the nuclei of the first atomic element and the electromagnetic field of the apparatus produces an NMR response which is tunable with field intensity. If the first atomic element of interest is present and intimately comingled with a second atomic element of interest, as might occur in compounds, and if the second element of interest has a nuclear quadrupolar moment and if the molecular structure conditions are proper for it to have a nuclear quadrupolar resonance (NQR), then adjustment of the magnetic field intensity varies the NMR frequency of the first element of interest to coincide with the NQR frequency of the second element of interest. Energy is then transferred in an enhanced fashion between the nuclei of the first element of interest and the nuclei of the second element of interest. This increased ease of transfer of energy between the two nuclei under the foregoing conditions reduces the NMR response time of the first element thereby improving the detectability of that element. Implementation of this effect is the basis for the reduced detection time and the improved discrimination achieved in the apparatus of this invention. A second aspect of the discrimination capabilities of the apparatus is achieved by varying the elapsed time between successive observations of the NMR response of the first element of interest. An apparatus and method allow the detection and measurement of a first element of interest in a particular compound while rejecting the NMR response from the same element located in different compounds.

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San Antonio, TX, United States of America

William L Rollwitz