What unit is used to measure static magnetic field strength outside the magnet?

The unit used to measure static magnetic field strength outside the magnet is the Gauss. This unit is a measure of the strength of a magnetic field and is particularly suitable for expressing the weaker magnetic fields found outside of MRI magnets.

In the context of magnetic resonance imaging, the strength of the static magnetic field generated by the MRI machine is typically measured in Tesla. One Tesla is equivalent to 10,000 Gauss, which reflects the stronger magnetic fields generated inside the MRI machine compared to the weaker fields present outside. While both Tesla and Gauss are valid units for measuring magnetic field strength, Gauss is specifically employed to express the lower magnetic field strengths encountered in the surrounding environment of the magnet.

Hertz, on the other hand, is a unit of frequency and is not applicable in the context of measuring magnetic field strength. The Newton is a unit of force, also irrelevant to magnetic field strength measurements. Thus, Gauss is the appropriate choice for quantifying the static magnetic field strength observed outside the magnet.