Metrohm 807 Dosing Unit - Manual (Page 29)

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3 Installation
807 Dosing Unit
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3.7 Disassembling the dosing unit
Generally speaking, it is not necessary to disassemble the dosing unit
when reagents are replaced. Thanks to the low exchange volume of only
a few microliters, and thanks to the EMPTY/Emptying and PREP/Pre-
paring functions, which every control unit for the Dosino has, a reagent
in a dosing unit can be replaced readily and without any large loss of
reagent.
We recommend that inspections of pistons and cylinders be carried out
regularly for each dosing unit (e.g. every six months). If alkali, corrosive or
highly concentrated reagents are used, then shorter (possibly weekly)
intervals will be called for. The glass cylinder itself could become corroded
by aggressive alkalis, or solids could crystallize out of the solution. In the
case of alkali reagents, the use of dosing units with ETFE cylinders is to be
recommended.
3.7.1 Disassembling the dosing unit
Dismantling the dosing system
1 Empty the dosing cylinder with the EMPTY/Emptying function of
the control device.
2 Rotate the Dosino on the dosing unit to the right all the way to the
UNLOCK marking.
3 Lift the Dosino.
4 Loosen the dosing unit on the bottle.
5 Remove the filling tubing.
6 Remove the storage vessel and the holder.