1.3.1 Test Method A—A sample of the material is obtained, the mass of each individual particle is determined and recorded. Test Method A is the most rigorous. It is most easily implemented for small sized rock that can be handled manually, or for very limited samples of large pieces.

1.3.2 Test Method B—A sample of the material is obtained, grouped into mass ranges. Each pile within a given range has its mass determined.

1.3.3 Test Method C—A sample of the material is obtained, the size of each particle is measured and grouped into size ranges, and the size ranges are converted to mass.

1.3.4 Test Method D—A sample of the material is partitioned within a revetment, particle sizes are measured and grouped into size ranges, and the size ranges are converted to mass.

1.4.1 For purposes of comparing measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal or significant digits in the specified limits.

1.4.2 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.

1.5.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In the system, the pound (lbf) represents a unit of force (weight), while the units for mass is slugs. The slug unit is not given, unless dynamic (F = ma) calculations are involved.

1.5.2 The slug unit of mass is typically not used in commercial practice; that is, density, balances, and so on. Therefore, the standard unit for mass in this standard is either pound (lbm), kilogram (kg) or gram (g).

1.5.3 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This practice implicitly combines two separate systems of units; the absolute and the gravitational systems. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. As stated, this standard includes the gravitational system of inch-pound units and does not use/present the slug unit of mass. However, the use of balances and scales recording pounds of mass (lbm) or recording density in lbm/ft3 shall not be regarded as nonconformance with this standard.