Teslameter

a magnetometer for the measurement of the magnetic induction B or magnetic field intensity H = B/µ₀µ in a nonferromagnetic medium (μ₀ is the magnetic constant, and u. is the relative magnetic permeability of the medium). The instrument received its name from the tesla, the unit of magnetic induction in the International System of Units.

The most common teslameters are based on the induction principle and consist of an inductance coil and an electrical measuring instrument. When a change occurs in the magnetic flux linkage between the inductance coil and the magnetic field whose induction is to be determined, an electromotive force, which is measured by the instrument, is generated in the coil. In constant magnetic fields the flux linkage changes as a result of linear displacement, rotation, or vibration of the inductance coil; in variable magnetic fields the change in flux linkage results from a change in the magnitude and direction of the field. Fluxmeters are used as the measuring instruments in the case of constant fields; voltmeters, oscillographs, and other such devices are used in the case of variable fields.

In addition to induction teslameters, ferroprobe teslameters are also used, as well as teslameters with Hall generators, teslameters based on subatomic phenomena, and, in particular, teslameters based on nuclear magnetic resonance, electron paramagnetic resonance, superconductivity, and optical pumping (seeQUANTUM MAGNETOMETER).

Teslameters are used to measure the horizontal and vertical components of the geomagnetic field intensity vector—for example, in magnetic mapping and geological prospecting. They are also employed in research on magnetism, particularly for measuring the magnetic fields of the planets in the solar system and of the interplanetary medium.