Sources Of Error And Options For Correction - Sartorius YDK03MS Mode D'emploi

Operation

5.2 Sources of Error and Options for Correction

NOTICE
Incorrect procedure when adjusting the balance!
Remove the sample holder of the density determination kit prior to making
t
adjustments .
The formula used to determine the density of solid objects is sufficient to obtain
an accuracy of one to two decimal places . Depending on the accuracy required,
the following error and correction factors will need to be considered:
− effect of temperature on the density of the buoyancy liquid
− air buoyancy when weighing in air
− changes in the immersion depth of the iron pan when immersing the sample
− adhesion of the liquid to the span wire of the iron pan
− air bubbles sticking to the sample
Some of the errors can be corrected mathematically . It is therefore necessary to
measure the temperature of the liquid and correct the liquid density accordingly
and to define the inner diameter of the vessel holding the liquid .
Effect of Temperature on Liquid Density
The density of the buoyancy liquid is temperature dependent . The change in density
per °C temperature change is as follows:
− 0 .02% for distilled water
− 0 .1% for alcohols and hydrocarbons
The change can show up in the third decimal place during the density determination .
To correct the liquid density in terms of temperature, proceed as follows:
− measure the temperature of the liquid using the thermometer supplied .
− The density of water can be found in the table in Chapter "5 .4 Density Values,"
page 22 and can be used for ρ (fl) .
14 Operating Instructions YDK03MS | YDK04MS