NMR tuning procedure

Patent · Tue Jun 03 04:00:00 EDT 1986

OSTI ID:5655791

Hill, H D

A method is described of adjusting a variable impedance RF probe of a quadrature sensitive Fourier transform NMR spectrometer, comprising the steps of: (a) directing a continuous wave RF signal to a network including a terminating fixed impedance of known characteristic in place of the variable impedance RF probe, (b) obtaining and storing the amplitude of the signal affected by the terminating fixed impedance, (c) detecting in quadrature and storing the phase of the affected signal in relation to the phase of the transmitted signal, whereby a first impedance vector is derived and retained, (d) replacing the fixed terminating impedance with the variable impedance RF probe, (e) next directing a continuous wave RF signal to the variable impedance RF probe, obtaining and storing the amplitude of the signal affected by the variable impedance RF probe and detecting in quadrature and storing the phase of the variable impedance RF probe affected signal in relation to the phase of the continuous wave RF signal applied thereto to obtain a second impedance vector characterizing the presence of the variable impedance probe, and (f) altering the amplitude and phase of the signal affected by the variable impedance RF probe by varying electrical parameters of the probe to minimized a function of the first and second impedance vectors.

• Assignee: Varian Associates, Inc., Palo Alto, CA
• Patent Number(s): US 4593246
• OSTI ID: 5655791
• Country of Publication: United States
• Language: English

Related Subjects

440300* -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
AMPLITUDES
FOURIER TRANSFORM SPECTROMETERS
IMPEDANCE
MEASURING INSTRUMENTS
NMR SPECTROMETERS
QUADRATURES
RF SYSTEMS
SIGNALS
SPECTROMETERS
TENSORS
TUNING
VECTORS