【国外标准】 Standard Test Method for Determining Filtering Efficiency and Flow Rate of the Filtration Component of a Sediment Retention Device

5.1 This test method is used to determine the filtering efficiency and flow rate of the filtration component of a sediment retention device, such as a silt fence, a silt barrier, or a silt curtain, for specific soil tested.5.2 This test method may be used for the design of the filtration component of a sediment retention device to meet requirements of regulatory agencies in filtering efficiency or flow rate for the specific soil tested.5.2.1 The designer can use this test method to determine the spacing between sediment retention devices.5.3 This test method is intended for performance evaluation, as the results will depend on the specific soil evaluated. Unless testing with the default soil is desired, it is recommended that the user or representative perform the test to pre-approve products, as sediment retention device manufacturers are not typically equipped to handle or test soil requirements.5.4 This test method provides a means of evaluating the filtration component of sediment retention devices with different soils under various conditions that simulate the conditions that exist in a sediment retention device installation. This test method may be used to simulate several storm events on the same sediment retention device specimen. Therefore, the number of times this test is repeated per specimen is dependent upon the user and the site conditions.1.1 This test method is used to determine the filtering efficiency and the flow rate of the filtration component of a sediment retention device, such as a silt fence, silt barrier, or inlet protector.1.1.1 The results are shown as a percentage for filtering efficiency and cubic metres per square metre per minute (m3/m2/min) or gallons per square foot per minute (gal/ft2/min) for flow rate.1.1.2 The filtering efficiency indicates the percent of sediment removed from sediment-laden water.1.1.3 The flow rate is the average rate of passage of the sediment-laden water through the filtration component of a sediment retention device.1.2 This test method requires several specialized pieces of equipment, such as an integrated water sampler and an analytical balance, or a vacuum filtration system. At the client’s discretion, the test soil is either a site-specific soil or a soil that is representative of a target default gradation.1.3 The values stated in SI units are the standard, while the inch-pound units are provided for information. The values expressed in each system may not be exact equivalents; therefore, each system must be used independently of the other, without combining values in any way.1.4 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.1.5 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.