These are the world's most sensitive commercially available laboratory instruments for measuring anisotropy of magnetic susceptibility and bulk magnetic susceptibility in weak variable magnetic fields (field range from 2 A/m to 450 A/m, RMS-values).

The KLY-4S version measures the AMS of a slowly spinning specimen. One has to adjust the specimen only into three perpendicular positions. The measurement is rapid (about 2 minutes per specimen) and precise, profiting from many susceptibility determinations in each plane perpendicular to the axis of specimen rotation. Special software combines the measurements in three perpendicular planes plus one bulk value to create a complete susceptibility tensor. The errors in determination of this tensor are estimated using new method based on principles from multivariate statistics.

The KLY-4 version measures the AMS of an immobile specimen in the same way as originally developed for the KLY-2 Kappabridge. The specimen susceptibility is measured interactively with a personal computer in 15 different positions using a special holder with sample positions that correspond to the rotatable measuring design. The positions are changed manually and, using special software, the susceptibility tensor is calculated including the statistical errors in its determination