MAGNETIC HEAD CHARACTERISTIC MEASURING INSTRUMENT

PURPOSE:To attain a measurement in which a signal envelope is uniform and good by stretching a magnetic tape directly for the inner circumference surface of a rotary drum by the centrifugal force of the tape. CONSTITUTION:A magnetic tape 14 makes almost one round along an inner circumference surface 11 of a rotary drum 11, one end 14a of the magnetic tape 14 is fixed by a tape fixing part 22 through a slit 21 provided for the rotary drum 11 and the other end 14b is made free. As the drum rotates, the centrifugal force acts on the respective parts of the magnetic tape 14 and it is pressed on the inner circumference surface 11a of the rotary drum 11, the flow of air generated by the rotation also acts and the magnetic tape is stretched round the drum uniformly in an instant. A magnetic head 15 is connected to the magnetic tape 14, after that, records and reproduces in a position projecting by 10-20mum to the side of the circumference surface. Thus, the uniform envelope is obtained and the highly accurate measurement is not spoiled.