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US5300888A Expired / Lapsed US ⏱️ 0.0 years remaining

NMR thermal analyzer

Assignee: Commonwealth Scientific and Industrial Research Organisation
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Filing: 1990-10-29
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Granted: 1994-04-05
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Expires: 2010-10-29
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Abstract

Abstract A method is provided for carrying out proton magnetic resonance thermal analysis measurements. To this end, the method provides locating a sample within a coil forming part of an RF tuned circuit and applying a magnetic field to the sample. The sample is heated in accordance with a predetermined temperature regime. Pulsed RF energy is applied to the coil to generate a pulsed RF electromagnetic field which is applied to the sample. The magnitude of the magnetic field is adjusted to insure that the NMR frequency of the sample is substantially identical to the RF frequency. The resonant frequency of the tuned circuit is adjusted to compensate for temperature induced changes in the tuned circuit components and the sample. The energy of the pulsed RF energy is adjusted to obtain an optimum output from the RF tuned circuit. The RF tuned circuit output is recorded as a function of either time or temperature of the sample. A proton magnetic resonance thermal analyzer is further provided as well as a high temperature heater probe for nuclear magnetic resonance measurements.

Inventors

  • 👤 David S. Webster
  • 👤 Leo J. Lynch

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 07:57
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/30; G01R33/31; G01R33/32; G01R33/34; G01R33/34046; G01R33/34053

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 190 words
A method of carrying out proton magnetic resonance thermal analysis measurements, said method comprising the steps of: i) locating a sample within a coil forming part of an RF tuned circuit and applying a magnetic field to said sample, ii) heating said sample in accordance with a predetermined temperature regime, iii) applying pulsed RF energy to said coil to generate a pulsed RF electromagnetic field which is applied to said sample, and thereafter substantially simultaneously, iv) adjusting the magnitude of said magnetic field to ensure that the NMR frequency of said sample is substantially identical to the RF frequency, v) adjusting the resonant frequency of the tuned circuit, if necessary, to compensate for temperature induced changes in the tuned circuit components and sample, vi) adjusting the energy of said pulsed RF energy to obtain an optimum output from said RF tuned circuit, vii) recording the RF tuned circuit output as a function of either the time or the temperature of said sample, and viii) repeating steps (iv) to (vi) as necessary at each desired time or sample temperature to obtain an optimum RF tuned circuit output, and repeating step (vii).
Claim 2
Independent Claim 190 words
A method of carrying out proton magnetic resonance thermal analysis measurements, said method comprising the steps of: i) locating a sample within a coil forming part of an RF tuned circuit and applying a magnetic field to said sample, ii) heating said sample in accordance with a predetermined temperature regime, iii) applying pulsed RF energy to said coil to generate a pulsed RF electromagnetic field which is applied to said sample, and thereafter substantially simultaneously, iv) adjusting the magnitude of said magnetic field to ensure that the NMR frequency of said sample is substantially identical to the RF frequency, v) adjusting the resonant frequency of the tuned circuit, if necessary, to compensate for temperature induced changes in the tuned circuit components and sample, vi) adjusting the energy of said pulsed RF energy to obtain an optimum output from said RF tuned circuit, vii) recording the RF tuned circuit output as a function of either the time or the temperature of said sample, and viii) repeating steps (iv) to (vi) as necessary at each desired time or sample temperature to obtain an optimum RF tuned circuit output, and repeating step (vii).
Claim 3
Dependent Claim 21 words
A method as claimed in claim 1 wherein the magnetic field is controlled in accordance with the RF tuned circuit output.
Claim 4
Dependent Claim 48 words
A method as claimed in claim 1 wherein step (viii) is repeated a plurality of times to increase the signal to noise ratio of the measurement, the results of the individual measurements being added together and averaged, and the number of times step (viii) is repeated being adjustable.
Claim 5
Dependent Claim 28 words
A method as claimed in claim 3 wherein the rate at which measurements are taken in selectable in order to attain a preselected level of NMR signal saturation.
Claim 6
Dependent Claim 26 words
A method as claimed in claim 1 wherein steps (iv) to (vii) are repeated within a time in the range of from 30 to 75 seconds.
Claim 7
Dependent Claim 131 words
A proton magnetic resonance thermal analyzer comprising an RF tuned circuit including an RF coil into which an NMR sample is insertable, said RF coil being locatable in a magnetic field, magnetic field strength means to adjust the magnitude of said magnetic field, RF pulse means connected to said RF tuned circuit to supply same with pulsed RF energy, an RF controller connected to said RF pulse means to adjust the magnitude of said RF energy, an RF tuner connected to said RF tuned circuit and a heater to substantially increase the temperature of said sample above ambient temperature, wherein each of said magnetic field strength means, said RF controller, said RF tuner and said heater is connected to a central processing unit and is both simultaneously and individually controlled thereby.
Claim 8
Dependent Claim 131 words
A proton magnetic resonance thermal analyzer comprising an RF tuned circuit including an RF coil into which an NMR sample is insertable, said RF coil being locatable in a magnetic field, magnetic field strength means to adjust the magnitude of said magnetic field, RF pulse means connected to said RF tuned circuit to supply same with pulsed RF energy, an RF controller connected to said RF pulse means to adjust the magnitude of said RF energy, an RF tuner connected to said RF tuned circuit and a heater to substantially increase the temperature of said sample above ambient temperature, wherein each of said magnetic field strength means, said RF controller, said RF tuner and said heater is connected to a central processing unit and is both simultaneously and individually controlled thereby.
Claim 9
Dependent Claim 61 words
An analyzer as claimed in claim 6 wherein the output of said RF tuned circuit is connected to said central processing unit via a digitising means and a storage means is connected to said central processing unit, the output of said RF tuned circuit at the cessation of said RF pulsed energy being stored in digital form in said storage means.
Claim 10
Dependent Claim 92 words
A high temperature heater probe for nuclear magnetic resonance measurements, said probe comprising an elongate body having an opening at one end, a tubular former carrying an RF coil located within said opening with the electrical connections to said RF coil passing through said body, the interior of said former being dimensioned to receive an NMR sample holder, a heater coil non-inductively wound along said elongate body and a layer of heat resistant substantially proton deficient cement covering said heater coil and through which said electrical connections to said RF coil pass.
Claim 11
Dependent Claim 92 words
A high temperature heater probe for nuclear magnetic resonance measurements, said probe comprising an elongate body having an opening at one end, a tubular former carrying an RF coil located within said opening with the electrical connections to said RF coil passing through said body, the interior of said former being dimensioned to receive an NMR sample holder, a heater coil non-inductively wound along said elongate body and a layer of heat resistant substantially proton deficient cement covering said heater coil and through which said electrical connections to said RF coil pass.
Claim 12
Dependent Claim 64 words
A probe as claimed in claim 8 wherein said opening in said body comprises a cylindrical opening having a longitudinally extending slot extending between the interior of said opening and the exterior of said body, said slot extending approximately half the longitudinal extent of said body, and said RF coil connections passing from said opening through said slot to the exterior of said body.
Claim 13
Dependent Claim 43 words
A probe as claimed in claims 8 or 9 wherein said RF coil is located in a groove cut in the exterior of said tubular former and said heater coil is located in a groove cut in the exterior of said elongate body.
Claim 14
Dependent Claim 31 words
An analyzer as claimed in claim 6 wherein said RF coil and heater comprise the RF coil and heater of the probe as claimed in claims 7, 8, 9 or 10.
Claim 15
Dependent Claim 99 words
An analyzer as claimed in claim 6 further comprising temperature heater probe for nuclear magnetic resonance measurements, said probe comprising an elongate body having an opening at one end, a tubular former carrying an RF coil located within said opening with the electrical connections to said RF coil passing through said body, the interior of said former being dimensioned to receive an NMR sample holder, a heater coil non-inductively wound along said elongate body and a layer of heat resistant substantially proton deficient cement covering said heater coil and through which said electrical connections to said RF coil pass.
Claim 16
Dependent Claim 64 words
An analyzer as claimed in claim 12, wherein said opening in said body comprises a cylindrical opening having a longitudinally extending slot extending between the interior of said opening and the exterior of said body, said slot extending approximately half the longitudinal extent of said body, and said RF coil connections passing from said opening through said slot to the exterior of said body.
Claim 17
Dependent Claim 41 words
An analyzer as claimed in claim 13, wherein said RF coil is located in a groove cut in the exterior of said tubular former and said heater coil is located in a groove cut in the exterior of said elongate body.

References Cited (Backward Citations)

US3502964A Cited
AU1490083A Cited
US4461996A Cited
EP0337908A1 Cited
EP0343858A2 Cited
US4914608A Cited
US5015954A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-04-04 1997-10-04 1998-04-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-04-04 2001-10-04 2002-04-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-04-04 2005-10-04 2006-04-05 $7700.00 Window Closed / Lapsed

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