1) Measuring instrument 
The permeameter is an instrument for rapidly measuring the electromagnetic permeability of samples of iron or steel with sufficient accuracy for many commercial purposes. The name was first applied by Silvanus P. Thompson to an apparatus devised by himself in 1890, which indicates the mechanical force required to detach one end of the sample, arra...
instrument for measuring permeability
an apparatus used to determine the relation between the magnetic flux density and the magnetic field strength in a sample of magnetic material which may be in the form of a stack of flat strips, a flat rectangular bar or a straight rod and which is placed centrally in a coil former carrying test windings of the apparatus, the ends of the sample pro...instrument intended for the determination of the magnetic characteristics of substances