ANSI INCITS 163

Abstract

This standardp rovidest he mechanical,p hysical, and magnetic properties of a low-friction disk with a diameter of 130 mm (5.118 inches) and with a typical recording density of 38 tracks per millimeter (tpmm) (960 tracks per inch (tpi)) and 402 flux transitions per millimeter (ftpmm) (10 200 flux transitions per inch (ftpi)) at a radius of 33,02 mm (1.300 inches). This standardd efinest he requirementsa nd supporting test methodsn ecessaryto ensurea cceptable performancel evelsi n the context of the generala pplication refeiencedi n 1.1. It is distinct from a specification in that it delineatesa minimum of restrictions consistentw ith compatibility of media characteristics. The performancel evelsc ontainedi n this standard representt he minimum acceptablele velso f performancef or typical applications.T hey, therefore,r epresent the performancel evelst hat the media should meet or surpassd uring their useful life. The performancel evelsi n theses tandardsa re intended asg uidelines to prospectiveu sersa nd should not be employed ass ubstitutesf or purchases pecifications. Quantitativep erformancel evelst hat must be met or exceededin order to comply with this standarda re givenw hereverp ossible.I n all casesi,n cluding thosei n which quantitativel imits for requirementsfa lling within the scopeo f this standarda re not statedb ut are left to agreemenbt etweeni nteracting parties,s tandardt est methodsa nd measuremenpt roceduress hall be usedt o determine such quantities. SI units are the original dimensioni n this standard. Conversionso f tolerancedd imensionst o customary U.S. engineeringu nits (similar to British Imperial units) haveb eend one in this standarda ccordingt o Method A of International Standardf or TolerancedD imensions- Conversionf rom Inchesi nto Millimetres and Vice Versa, IS0 370-1975, except as noted. Method A should be usedf or economyu nlessa requirementf or absolutea ssuranceo f a fit justifies useo f Method B. In the national standardso f IS0 membern ations, additional rounding may be done to produce “preferred” values.T hesev aluess hould lie within or closet o the original tolerancer anges