ASTM D8326-20

1.1 This practice is used to measure the kinetic energy of rainfall simulators used by laboratories to evaluate soil erosion. The kinetic energy of raindrops is an important factor that should be considered when conducting soil erosion studies. Using the data collected from determining the raindrop size, this practice provides a method to uniformly calculate the kinetic energy which can be used to compare results from different laboratories.

1.2 Many types of Erosion Control Products (ECPs) are evaluated for their ability to reduce soil erosion in laboratory and field settings using rainfall simulators. Rainfall simulators are used with test plots to simulate a specific condition that is or may be expected in the field. Rainfall simulators typically use drop emitters, sprinklers, or nozzles to create the raindrops. Each device produces different drops and since the rainfall simulators can be configured to produce different raindrop sizes and fall heights, the kinetic energy will be different. Therefore, the kinetic energy must be calculated for a given set of conditions in order to properly understand the impact of erosion for bare soil and the ECP.

1.3 The upper limit of the size of a raindrop is generally accepted to be 7 mm. While it is possible to get a raindrop size between 6 and 7 mm occasionally, it is not common to get raindrop sizes above 6 mm.

1.4 Units-The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.

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

1.6 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.