ASTM F 2358 : 2004

1.1 This guide covers a nondestructive procedure to determine the form of clean, dry sapphire substrates.

1.2 This guide is applicable to substrates 25 mm or larger in diameter, with a minimum thickness of 100 μm. This guide is independent of surface finish.

1.3 The measurements described in this guide may be applied to the entire global surface of the substrate, or to smaller localized areas.

1.4 The value of the measurements described in this guide will be affected by the amount of edge exclusion (that is, the area around the perimeter of the part which is ignored). The amount excluded should be agreed upon by the producer and consumer using this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.