Abstract: The magnetic shield preferably encloses circuitry connected to equipment in a high magnetic field (e.g., two transformers of a gas flow transducer in an MRI suite). The magnetic shield is preferably oriented so that its long axis is aligned with the axis of maximum magnetic sensitivity of the enclosed circuitry. The shield shunts external magnetic flux around the enclosed circuitry to protect the circuitry from saturation in the high magnetic field. The shield is preferably made from hot rolled low carbon steel which has relatively low permeability and saturates slowly. The physical size and construction of the shield reduces magnetic flux within the shield with a minimal amount of iron. In another embodiment, a magnetic field sensor is mounted within the shield to measure the magnetic field affecting the enclosed circuitry. The sensor is coupled to an external circuit which indicates when the magnetic flux is strong enough to affect the operation of the enclosed circuitry.

Abstract: The magnetic shield preferably encloses circuitry connected to equipment in a high magnetic field (e.g., two transformers of a gas flow transducer in an MRI suite). The magnetic shield is preferably oriented so that its long axis is aligned with the axis of maximum magnetic sensitivity of the enclosed circuitry. The shield shunts external magnetic flux around the enclosed circuitry to protect the circuitry from saturation in the high magnetic field. The shield is preferably made from hot rolled low carbon steel which has relatively low permeability and saturates slowly. The physical size and construction of the shield reduces magnetic flux within the shield with a minimal amount of iron. In another embodiment, a magnetic field sensor is mounted within the shield to measure the magnetic field affecting the enclosed circuitry. The sensor is coupled to an external circuit which indicates when the magnetic flux is strong enough to affect the operation of the enclosed circuitry.