ABSTRACT

Fortakingsinglesamplesoftheriverwater,standardinstrumentshave beendevised(Fig.8.2(a)).Thedisplacementsampler,showninFig.8.2(b), recommendedforthedeterminationofDOcanbeusedforgeneralsampling inopenchannels.Theinletisopenedwhenthecontainerisattherequired depthandthewaterisfedintothebottomofthebottle.Whenthewhole containerisfullthewaterflowsfromtheexit,andtheflowshouldcontinue untilthebottlecontentshavebeenchangedseveraltimesbeforethesampler isremoved.Numeroussamplerdesignshavebeenadoptedinconjunction withstudiesofsuspendedsolids,thelatterhavingreceivedparticularattentionintheUnitedStates.AselectionoftheseisshowninFig.8.3.Ineach containerthereisaglassorpolythenebottle.