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volumetric measurement & liquid handling
007
Volumetric flasks are mainly used
for preparation of highly accurate
solutions.
First add the exact weight of the
product inside the flask. Fill the flask
about half the volume and mix the
content.
Then fill again until the level reaches
a bit lower than calibration ring mark.
Adjust
the
temperature
of
flask and the
content to 20°C.
Add a little more
liquid so that the
meniscus will be
exactly at the same
level of the ringmark.
Pay attention to
read themeniscusat
theeye level alsonot
to wet the inner neck
wall above the ring
mark.
how to use
volumetric flasks
Fill theburetteabit higher than the “0” level.
Toactivate thestopcock, drain thesolution
but never below the “0” mark.
Pay attention there will be no air bubbles
left in the burette.
Fill more solution
above 10 mm of the
“0” mark. Do not wet
the burettewall above
the liquid level.
By focusing the
meniscus at eye level
drain the solution to
the exact “0” mark.
Wipe off the drops
at the stopcock tip and
slowly start the titration.
When color changes
stop the titration and
waitforthe30seconds.
Wipe off the
remaining drop since
this is also the part of
themeasuredvolume.
how to use
burettes
Cylinders are mainly used for the
exact measurement of liquid volumes.
First fill the cylinder with liquid and
wait until the residual liquid on the
wall will to filter down.
Then read the
volume level from
the
cylinders
volume graduation
chart.
Pay attention to
read the volume
level at the eye
level. Do not wet
the inner neck
wall above the
calibration mark.
how to use
measuring cylinders
Fill the liquid max 5 mm above the
volume mark. Wipe off the outer surface of
the pipette.
Hold the pipette at eye level and place the
tip to thewall of a beaker with a slight angle.
Discharge the
access
volume
until the meniscus
reaches
the
calibration mark.
When the level of
the liquid reaches to
the tip wait according
to waiting time.
When the waiting
time is over, wipe
the tip gently pulling
upwards on the
beaker wall and
transfer the liquid.
If there is still any
residual liquid left in
the tip, never blow
out.
how to use
pipettes
Mixing cylinders are mainly used
for the exact measurement of liquid
volumes.
First fill the cylinder with liquid and
wait until the residual liquid on the
wall to filter down.
Then read the
volume level from
the
cylinders
volume graduation
chart.
Later add the
precise
weight
of the substance
and dissolve it
by shaking the
cylinder.
how to use
mixing cylinders
Carefully weigh the empty and well
dried density bottle.
Fill the bottle up to 2/3 of the neck
level while avoiding air bubbles.
Adjust the bottle temperature to 20°C in a
thermostatic bath. Insert the stopper of the
bottle carefully. The capillary of the stopper
will discharge the liquid.
Dry the body of the bottle and the
stopper carefully by wiping with a tissue
paper. Pay attention not to remove
any liquid from the
capillary tube.
The liquid inside
of the bottle should
exactly be at the
same level with the
upper end of the
capillary tube.
Final step is
weighing the filled
density bottle and
calculating
the
density.
how to use
density bottles