【国外标准】 Standard Guide for Selection of Methods of Particle Size Analysis of Fluvial Sediments (Manual Methods)

5.1 This guide is general and useful in helping the user to determine an appropriate manual test method for determining the particle size distribution of fluvial sediments. The suggested test methods are not described in this guide, but references are given so that the user may obtain more information about each test method.5.2 It should be noted that different test methods may and often times do produce different particle size distributions for the same sample. This is due in part to the different test methods requiring native or distilled water, differences in dispersion methods used, and differences in what the test method is measuring, that is, physical or sedimentation diameter.1.1 This guide covers the selection of methods for determining the size distribution of fluvial sediments particles in the range greater than 0.45 μm using manual methods. Manual methods are defined as those methods that require the operator to do some actual measurements and calculations. An automated method would be one which, after the sample is prepared and inserted into an instrument, the instrument (machine) does the measuring and calculations, not the operator. Not all manual methods are presented in this guide. However, where available, at least two methods for each particle size range are given.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 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.1.4 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.