Mechanical compactors are commonly used to replace the hand compactors required for Test Methods D698 and D1557 in cases where it is necessary to increase production.

The design of mechanical compactors is such that it is necessary to have a calibration process that goes beyond determining the mass and drop of the hammer.

Note 1-The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria in Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/and the like. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.