ASTM D4787-93(1999) PDF

1.1 This practice covers procedures that may be used to allow the detection of discontinuities in nonconductive linings applied to concrete substrates.

1.2 Discontinuities may include pinholes, internal voids, holidays, cracks, and conductive inclusions.

1.3 This practice describes detection of discontinuities utilizing a low voltage wet sponge holiday detector and a high voltage pulsating or continuous dc spark tester. Linings with thickness in excess of 20 mils must be tested utilizing high voltage spark testing equipment.

1.4 This practice describes procedures both with and without the use of a conductive underlayment.

1.5 The values stated in the inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

1.6 This standard does not purport to address all of the safety problems, 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 limitations prior to use. For a specific hazard statement, see Section 7.