A SET FOR MEASURING THE COERCIVE FORCE OF MAGNETIC TAPES

A set for measuring the coercive force of magnetic tapes to 120 kA/m i s presented. The set is capable of inducing alternative magnetic field 190 kA/m in a miniature solenoid. A desired value and hysteresis loop are depicted simultaneously on an indicator and oscilloscope, respect ively. Pulse modulation of sinusoidal current of the solenoid is used thus providing escape of forced cooling. Electron balance of noise is also used and the labels of field strength and coordinate axes are for med on the screen at the same time. Coercive force is measured when la bel coincides with horizontal axis and reading of an indicator is reco rded.