Magneto-Acoustic Sensing Device for Particulate Magnetic Media
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
A device is described for sensing magneto-acoustic effects in particulate magnetic material in a background matrix that may be liquid or solid. Also conceivable is an embodiment for monitoring the degree of dispersion of magnetic particles in a magnetic ink in a fast, non-destructive manner. Such an embodiment is a valuable aid for in-situ monitoring the dispersion quality of magnetic ink in a coating line for magnetic tapes in a totally non-intrusive manner. The principle of the sensing device is illustrated below with respect to dispersion monitoring. Magnetic particles of, say, qFe2O3 or chromium dioxide, in an ink follow an oscillating magnetic field if the oscillation frequency is sufficiently low so that the period is not much shorter than the response time of the particles.