Abstract: Magnetic resonance methods are provided for determining the mass of samples in vials (1) in a production line, each sample having a net magnetisation capability, including the steps of applying a first magnetic field in a first direction in an interrogation zone (25) for creating a net magnetisation within a sample located within the interrogation zone (25), applying an alternating magnetic field in a second direction in the interrogation zone (25) for temporarily changing the net magnetisation of the sample located within the interrogation zone (25), monitoring energy emitted by the sample as the net magnetisation of the sample returns to its original state and generating an output signal whose current amplitude is proportional to the energy emitted, comparing the current amplitude with like data obtained from at least one similar sample of known mass, and determining the mass of the sample.

Abstract: A radio frequency (RF) probe (10) for a nuclear magnetic resonance check weighing system produces a uniform magnetic field at the center of RF probe (10), has minimal sensitivity to electrical interference from external sources, shapes the magnetic field to minimize cross coupling from packages such as drug vials (22) not under test, and presents minimal airflow obstruction. RF probe (10) includes a coil (100) with a plurality of conductive loops (102, 104) having a rectangular cross section carried inside two opposing, rectangular cross section housings (106, 108), respectively. Housings (106, 108) are spaced apart and in parallel, creating an “open probe” configuration permitting a conveyor belt (28) carrying vials (22) whose contents are to be checked to pass between housings (106, 108), and allows airflow surrounding the vials (22) and conveyor belt (28) to pass substantially without obstruction.

Abstract: A method (10) insures that the characteristics of the magnetic field used in a magnetic resonance check weighing system (20) for samples in vials (22) on a production line track deviations from the resonant frequency of the sample. The method (10) includes the steps of obtaining (50) a free induction decay signal from a magnetic resonance measurement of the sample, monitoring (52) from the free induction decay signal the deviation of the resonance frequency of the magnetic resonance measurement from a preselected resonance frequency; and adjusting (62) the magnetic field to maintain the preselected resonance frequency.

Abstract: A method (10) insures that the characteristics of the magnetic field used in a magnetic resonance check weighing system (20) for samples in vials (22) on a production line track deviations from the resonant frequency of the sample. The method (10) includes the steps of obtaining (50) a free induction decay signal from a magnetic resonance measurement of the sample, monitoring (52) from the free induction decay signal the deviation of the resonance frequency of the magnetic resonance measurement from a preselected resonance frequency; and adjusting (62) the magnetic field to maintain the preselected resonance frequency.

Abstract: Magnetic resonance methods are provided for determining the mass of samples in vials (1) in a production line, each sample having a net magnetisation capability, including the steps of applying a first magnetic field in a first direction in an interrogation zone (25) for creating a net magnetisation within a sample located within the interrogation zone (25), applying an alternating magnetic field in a second direction in the interrogation zone (25) for temporarily changing the net magnetisation of the sample located within the interrogation zone (25), monitoring energy emitted by the sample as the net magnetisation of the sample returns to its original state and generating an output signal whose current amplitude is proportional to the energy emitted, comparing the current amplitude with like data obtained from at least one similar sample of known mass, and determining the mass of the sample.

Abstract: A radio frequency (RF) probe (10) for a nuclear magnetic resonance check weighing system produces a uniform magnetic field at the center of RF probe (10), has minimal sensitivity to electrical interference from external sources, shapes the magnetic field to minimize cross coupling from packages such as drug vials (22) not under test, and presents minimal airflow obstruction. RF probe (10) includes a coil (100) with a plurality of conductive loops (102, 104) having a rectangular cross section carried inside two opposing, rectangular cross section housings (106, 108), respectively. Housings (106, 108) are spaced apart and in parallel, creating an “open probe” configuration permitting a conveyor belt (28) carrying vials (22) whose contents are to be checked to pass between housings (106, 108), and allows airflow surrounding the vials (22) and conveyor belt (28) to pass substantially without obstruction.