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) for reducing or eliminating the effects of proximate samples on the NMR measurement of the mass of a test sample in a NMR check weighing system (24) for samples on a production line. The test sample is in a container (22) on a production line with the plurality of proximate samples each also in a container (22) on the production line. Method (10) includes determining cross coupling weighing factors for a plurality of samples in proximity to the test sample, magnetic resonance measuring of the test sample and proximate samples, the step of magnetic resonance measuring of the test sample and proximate samples providing data representative of each measurement; and applying weighing factors to the data representative of each measurement compensating for the proximate sample effects.

Abstract: A method (10) for reducing or eliminating the effects of proximate samples on the NMR measurement of the mass of a test sample in a NMR check weighing system (24) for samples on a production line. The test sample is in a container (22) on a production line with the plurality of proximate samples each also in a container (22) on the production line. Method (10) includes determining cross coupling weighing factors for a plurality of samples in proximity to the test sample, magnetic resonance measuring of the test sample and proximate samples, the step of magnetic resonance measuring of the test sample and proximate samples providing data representative of each measurement; and applying weighing factors to the data representative of each measurement compensating for the proximate sample effects.

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.