2.9
KF: Filling the titration vessel with solvent
The solvent is pumped from the solvent bottle into the titration vessel by pushing down the front part of the rocker
switch on the titration stand TM 235 KF.
Pump solvent (approx. 35-40 ml) into the titration vessel until the titration tip and the electrode are completely
immersed (Fig. 31).
Fig. 31
2.10
Replacing the Glass Cylinder and the PTFE Piston
As a rule, the hoses and cylinders will contain chemicals which may spill or be splashed around in the course
of disassembly. The relevant safety precaution measures applicable to the handling of the chemicals concerned
have to be absolutely observed!
Replacing the glass cylinder and the piston does not require any additional tools. In certain cases the piston
extractor has to be used.
1. Remove the interchangeable unit from the base unit
2. Unscrew the hose between the glass cylinder and the valve from the glass cylinder.
3. Rotate the UV protection 5 to 6 times to the left to loosen it.
4. Remove the UV protection and pull out of the glass cylinder together with the piston inside it.
5. Insert a new glass cylinder and piston (Fig. 32) into the interchangeable unit.
Tighten the UV protection again by rotating it 5 to 6 times to the right.
6. The piston rod must project 0.5 cm out of the interchangeable unit (Fig. 33).
7. Tilt the unit forward until the slanted bottom side is in flat contact with the lab table (Fig. 34).
This forces the piston into its correct position.
If the piston be forced too far into the glass cylinder, simply pull it out and place it in the correct position
according to the procedure described above.
169
35-40 ml
Filling