magnetometer

An instrument used for measuring the magnitude and direction of a magnetic field.

An instrument used to measure magnetic forces or the strength of a magnetic field, especially one used to measure the intensity of the earth’s magnetic force at any place.

An instrument for measuring the intensity of magnetic forces; also, less frequently, an instrument for determining any of the terrestrial magnetic elements, as the dip and declination.

An instrument used to measure the intensity and direction of a magnetic field, especially at points on the Earth‘s surface.

a meter to compare strengths of magnetic fields