Sources Of Error And Options For Correction - Sartorius YDK04 User Manual

Sources of Error and Options for Correction

Theaboveformulatodeterminethe
densityofsolidobjectsissufficiently
accuratefordeterminingthedensity
totwodecimalplacesdependingon
samplesvolume�Thisdensitykitis
designedfordeterminingdensityof
10g–2kgweightofsamples�
Dependingontheaccuracyrequired,the
followingerrorandcorrectionfactorswill
needtobeconsidered:
– effectoftemperatureonthedensityof
thebouyancyliquid
– airbouyancywhenweighinginair
– changesintheimmersiondepthofthe
immersionframewhenimmersingthe
sample
– adhesionoftheliquidtotheimmersion
frame
– airbubblesstickingtothesample�
Someoftheerrorscanbecorrected
mathematically�Todothis,youhaveto:
– measurethetemperatureoftheliquid
andcorrecttheliquiddensity
accordingly�
Effect of Temperature on the Liquid
Density
Thedensityofthebuoyancyliquidis
temperaturedependent�Thedensity
changeper°Ctemperaturechangeis
oftheorderof:
– 0�02%fordistilledwater
– 0�1%foralcoholsandhydrocarbons�
Inotherwords,thiscanshowupinthe
thirddecimalplaceduringdensity
determination�
Tocorrecttheliquiddensitybasedon
temperature,proceedasfollows:
– measurethetemperatureoftheliquid
usingthethermometersupplied�
– thedensityofthemostcommon
buoyancyliquids,waterandethanol,
atthemeasuredtemperaturecanthen
befoundinthetableprovidedandused
forρ(fl)�
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