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© behr Labor-Technik 2013
249101
Before shutting the S 5 down
If you have finished work with the S 5 for the day, please
take a few precautions to make sure that the apparatus
will not be damaged during this interval of disuse.
— Sodium hydroxide and - to a lesser extent – boric
acid attack the pumps and tubing. With ambient
air, sodium hydroxide will form deposits of soda
(Na
2
CO
3
) which can clog the pump and tubings.
After the last distillation of the day, always rinse
the delivery lines (pumps and tubing) and close
the storage bottles.
— The pH electrode must not be left standing dry; it
would dry out and become useless.
— The container must not be situated at a level
higher than the pumps.
Remove the PVC reagent feed tubes from the NaOH
and H
3
BO
3
containers and insert them into the container
of distilled water, which you have placed nearby.
Open the water tap.
Inserting the sample vessel
Insert the steam delivery tube into an empty sample
vessel. Press the quick release fastener down and
insert the sample vessel.
Check to insure that the sample vessel is firmly seated
against the Viton stopper.
Switching the steam distillation
apparatus on
Close the protective door and turn the apparatus on
using the MAIN SWITCH.
In the main menu, select Options.
Rinsing
The following display appears:
Select MANUAL ENTRY. The display will then appear
as follows:
NaOH
Steam
Dil. H2O
==>><<==
Select NaOH and hold the operating control knob
depressed until the sample vessel has been filled up to
about three quarters.
Remove the PVC reagent tube for NaOH out of the con-
tainer of distilled water. Hold the operating control knob
depressed until no more water flows into the sample ves-
sel.
Empty the sample vessel and insert it again. The NaOH
pump and delivery lines have now been rinsed and
emptied.
Conserving the pH electrode
Make sure there is enough KCl solution in the protec-
tion vessel so as to keep the electrode membrane wet.
If necessary, refill with KCl solution (3 mol/l). See user‘s
manual of your titrator.
Put the electrode into the protection vessel. Push it
down gently so as to fit it into the mouth of the vessel.
Rinsing the tubes
Fill a container with distilled water and place it near the
steam distillation unit.
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