1.1 This test method describes procedures for measuring the energy that enters the penetrometer drill rod string during dynamic penetrometer testing of soil due to the hammer impact. 1.2 This test has particular application to the comparative evaluation of N-values obtained from the Standard Penetration Tests (SPT) of soils in an open hole as in Test Method D1586 and Practice D6066. This procedure may also be applicable to other dynamic penetrometer tests. 1.3 The values stated in SI units are to be regarded as standard. The inch-pound units given in parentheses are mathematical conversions which are provided for information purposes only and are not considered standard. 1.4 Limitations -This test method applies to penetrometers driven from above the ground surface. It is not intended for use with down-hole hammers. 1.5 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026. 1.6 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to how the data can be applied in design or other uses, since that is beyond its scope. Practice D6066 specifies how these data may be normalized. 1.7 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.