1、Designation:D632622Standard Practice forSelection of Maximum Transit-Rate Ratios and Depths forthe U.S.Series of Isokinetic Suspended-Sediment Samplers1This standard is issued under the fixed designation D6326;the number immediately following the designation indicates the year oforiginal adoption or
2、,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the maximum transit-rate ratios anddepths for selected suspended-
3、sediment sampler-nozzle-container configurations.1.2 This practice explains the reasons for limiting thetransit-rate ratio and depths that suspended-sediment samplerscan be correctly used.1.3 This practice give maximum transit-rate ratios anddepths for selected isokinetic suspended-sediment sampler/
4、nozzle/container size for samplers developed by the FederalInteragency Sedimentation Project.1.4 Throughout this practice,a samplers lowering rate isassumed to be equal to its raising rate.1.5 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mat
5、hematicalconversions to SI units that are provided for information onlyand are not considered standard.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,a
6、nd environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International
7、 Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD4410 Terminology for Fluvial SedimentD4411 Guide for Sampling Fluvial Sediment in Motion3.Terminology3.
8、1 Definitions:3.1.1 For definitions of terms used in this practice,refer toTerminology D1129 and Terminology D4410.3.2 Definitions of Terms Specific to This Standard:3.2.1 approach angle,nthe angle between the velocityvector of the approaching flow and the centerline of the nozzle.3.2.2 approaching
9、flow,nflow immediately upstream of anozzles entrance.3.2.3 bag sampler,na suspended-sediment sampler thatuses a flexible collapsible bag as a sample container.3.2.4 compression rate,nthe rate at which the air iscompressed in the sample container and is a function of thespeed at which the sampler is
10、lowered in the sampling vertical.3.2.5 isokinetic,adjthe conditions under which the direc-tion and speed of the flowing water/sediment mixture areunchanged upon entering the nozzle of a suspended-sedimentsampler.3.2.6 maximum transit rate,nthe maximum speed atwhich the sampler can be lowered and rai
11、sed in the samplingvertical and still have the sample collected isokinetically.3.2.7 transit rate,nthe speed at which the suspendedsediment sampler is lowered and raised in the samplingvertical.3.2.8 transit-rate ratio,nthe ratio computed by dividingthe transit rate by the mean stream velocity in th
12、e vertical beingsampled.4.Summary of Practice4.1 This practice describes the maximum transit-rate ratiosand depths that can be used for selected isokinetic suspended-sediment sampler/nozzle/container configurations to ensureisokinetic sampling.(Manufacturing differences in the produc-tion of sedimen
13、t samplers may result in some samplers notcollecting a sample isokinetically.It is the users responsibilityto ensure through calibration that the sampler does collect asample isokinetically.Guide D4411 describes a process forchecking calibration of suspended-sediment samplers.)1This practice is unde
14、r the jurisdiction of ASTM Committee D19 on Water andthe direct responsibility of Subcommittee D19.07 on Sediments,Geomorphology,and Open-Channel Flow.Current edition approved May 1,2022.Published June 2022.Originallyapproved in 1998.Last previous edition approved in 2014 as D6326 08(2014).DOI:10.15
15、20/D6326-22.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO
16、Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.15.Significance and Use5.1 This practice describes the maximum transit-rate ratiosand depths that can be used for selected isokineti
