12
3
Replacing the dosing unit (installation and dissambly)
As a rule, the need for replacing the dosing unit occurs only rarely. The dosing unit has to be replaced, if
such a replacement becomes necessary as a result of a defect or of an inspection of the titration unit.
The dosing unit is equipped with lateral ribs around its circumference, with one of these ribs being in double
design. This double rib serves as a mark for the correct placement of the dosing unit (
&
Fig. 3, Pos. 2 resp.
Fig. 9, Pos. 2).
Important note: The disassembly of the dosing unit as such is only possible using a special tool (TZ 3630)
and should only be done by experienced persons. The sealing lip of the PTFE piston and the sealings of the
liquid system may be damaged or incorrectly positioned in the course of such a disassembly. As a result, ti-
tration liquid would leak in unwanted places.
!
Caution! Wear protective glasses!
3.1 Piston Burette TITRONIC
â
â
â
â
96
Ü
Switch the Piston Burette TITRONIC
â
96 on (
&
Fig. 8 of the
Operating Instructions
TITRONIC
â
96)
Ü
Press the violet key of the manual key button, dose until the display shows between 18.00 and 19.00 ml.
Ü
Switch the Piston Burette TITRONIC
â
96 off.
Ü
Unlock the dosing unit by rotating it to the left (anticlockwise,
&
Fig. 1).
Ü
Keep both keys of the manual key button depressed (
&
Fig. 5 + Fig. 6), furthermore switch the titration
unit on. (This somewhat awkward way of proceeding is necessary in order to prevent the inadvertent start
of the process under all circumstances).
Ü
The motor of the Piston Burette TITRONIC
â
96 will automatically move the piston rod up. The display will
show <<uP>>.
Detaching the dosing unit:
Placement of the dosing unit:
Fig. 1 Unlocking
Fig. 2 Removal
Fig. 3 Placement
Fig. 4 Locking
Pos. 1
Pos. 2
Pos. 1
Pos. 2
Pos. 1
Pos. 2
M
Pos. 1
Pos. 2
Ü
The process is completed as soon as the display shows <<End>>, the dosing unit can be removed
(
&
Fig. 2).
Ü
Switch the Piston Burette TITRONIC
â
96 off.
Fig. 5
Fig. 6
Ü
Set on new (inspected, if necessary repaired) dosing unit vertically. When doing so the „M“ double rib
(
&
Fig. 3) must point at the position 2 of the casing marking. Subsequently, switch the Piston Burette
TITRONIC
â
96 on. The running motor will now pull the dosing unit downwards.
Ü
As soon as the dosing unit moving downwards has reached the edge of the casing, the Piston Burette
TITRONIC
â
96 has to be switched off, and the dosing unit has to be locked manually (
&
Fig. 4). In or-
der to fill the Piston Burette TITRONIC
â
96 with titration solution, proceed as it is described in chapter
3.1 „Rinsing / Initial filling“ of the
Operating Instructions
(
&
Fig. 9 and 10).
