Abstract: A method for manufacturing a thick asphalt sheet comprises preparing a thick sheet material made of non-woven fabric of synthetic material, passing said sheet material through at least one pair of pressing rolls from the upper side to the lower side and feeding and storing molten petroleum asphalt into a concavity formed on the upper side of said pair of rolls, whereby the molten petroleum asphalt is pressed into the sheet material when said material passes through said pair of rolls, thereby forming an asphalt sheet. The asphalt sheet thus manufactured is immediately led onto a processed ground surface to form a waterproofing layer thereon.

Abstract: A vibration measurement head is used to measure the type of vibration set up in a magnetic head by the frictional contact of the magnetic head with magnetic media. The head is the same shape as such a magnetic head and consists of piezoelectric material in which vibration generates an electrical charge. This charge is measured, thereby providing a simulated measurement of the vibration occuring in a magnetic head.