5.1 This test method is designed to measure the permeability to air of a small sample of rock. By extrapolation, this test method also determines an equivalent of the liquid permeability. This parameter is used to calculate the flow through rock of fluids subjected to a pressure differential.

1.1 This test method covers the determination of the coefficient of specific permeability for the flow of air through rocks. The method establishes representative values of the coefficient of permeability of rocks or well-indurated soils.

1.2 This test method is limited to permeability values greater than 9.869 × 10-18 m² (0.01 millidarcy), and is limited to rocks free of oil or unctuous matter.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.

1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.

1.4.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering design.

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 limitations prior to use.