Magnetic Balance

magnetic balance

[mag′ned·ik ′bal·əns] (engineering) A device for determining the repulsion or attraction between magnetic poles, in which one magnet is suspended and the forces needed to cancel the effects of bringing a pole of another magnet close to one end are measured. Any device for measuring the small forces involved in determining paramagnetic or diamagnetic susceptibility.

Magnetic Balance

 

an instrument operating according to the principle of a pendulum, torsion, or beam balance; used for measurements of magnetic susceptibility of various objects, of the anisotropy of their susceptibility, or (less frequently) of the horizontal and vertical intensity components of the earth’s magnetic field.

The susceptibility of a magnetic material is determined by measuring the force with which a sample in the form of an elongated cylinder is drawn into the field of an electromagnet (the Gouy method) or according to the force acting on a small sample placed in a heterogeneous magnetic field (the Faraday method). A null measurement method is usually used; in this case the force or force moment is compensated by the force of interaction of special electromagnets.

Magnetic balances are calibrated by means of standard substances with known magnetic susceptibility, determined from their magnetization curves. The sensitivity of a magnetic balance can reach 10-8 newton per scale unit; the error of relative measurements is of the order of 1 percent.

REFERENCES

Chechernikov, V. I. Magnitnye izmereniia, 2nd ed. Moscow, 1969.
Chechurina, E. N. Pribory dlia izmereniia magnitnykh velichin. Moscow, 1969.
Selwood, P. Magnetokhimiia, 2nd ed. Moscow, 1958. (Translated from English.)
Borovik-Romanov, A. S., and N. Kreinas. “Magnitnye svoistva trekhvalentnykh ionov evropiia i samariia.” Zhurnal eksperimentaVnoi i teoreticheskoi fiziki, 1955, vol. 29, fasc. 6/12, p. 790.