| 摘要 |
PURPOSE:To evaluate crush resistance with high reliability within a short time by enabling the accelerated evaluation in the simulated state of an actual crush phenomenon, by using a mixture consisting of a fine cellulose powder and a fine silicon oxide powder. CONSTITUTION:Floated dust is sent into a tester 16 from the upper part of a dust generating cylinder 6 by clean air and diffused by the rotation of a disc to hold a high concn. dust atmosphere within the tester 16. The dust concn. in the vicinity of a magnetic head 8 is measured by a dust counter 10 through a measuring tube provided to the downstream side of the magnetic head 8 and the pressure of clean air sent by a regulator 3 is regulated so as to hold predetermined dust concn. As the dust 7 to be thrown in, a mixture consisting of a fine cellulose powder and a fine silicon oxide powder is used. In this case, the interior of the tester 16 is brought to a high concn. atmosphere and the magnetic head 8 is floated above a disc 9 to be evaluated while a time required in crushing is measured. |
