System Preparation; Sample Plates Of The Tw Alpha Plus Titration Sample Changer - SCHOTT TW alpha plus Mode D'emploi

2.4 System preparation

Fitting of a hose carrier
Please use the enclosed knurled screws to attach the hose carrier to the bore holes provided for this purpose
on the back panel.
When fastening the hoses and electrode cables afterwards, please avoid any kinking of the hoses and cables
during this process.
Changing the stroke height
The ex-factory setting of the stroke height is approx. 130 mm (half of the travel). It is possible to mechanically
change the stroke height using an internal switch. If very high containers are to be used, for instance, COD
containers, the connection of the middle switch is to be interrupted.
If the stroke height is to be modified, the casing has to be opened in any case. To do so, please pull off the
titration-head carrier, then remove the four screws along the front guidance key as well as the two upper and
the two lateral ones at the bottom. After removing the entire enclosure, the middle switch can be found to the
left of the guidance body.
Please note!! Do not change the setting of the upper limit switch since it is used to limit the travel.
Connection of a titration system
A data cable of the no. TZ 3084 type is used to connect the TW alpha plus Titration Sample Changer to a titra-
tion system, or with TZ 3088 directly to a computer. This is done using the upper of the 9-channel sockets on
the back panel, i.e. the (1) RS-232-C data communication interface. For further information, please refer to
chapter 6, "Connection to a computerized titration system".
Electrodes, titration tips, stirrer
The required electrodes and titration tips are to be inserted into the corresponding bore holes (NS 14,5) of the
titration head, e.g. of the no. TZ 1463 type. If a stirrer is used, it should also be connected to one of the bore
holes. The power supply of the stirrer is established via a cable which is to be attached to the titration head
and leads to the "Rührer/Stirrer" socket at the back panel of the TW alpha plus Titration Sample Changer.
The stirring speed can be adjusted by software commands. The max. rps of the built-in magnetic stirrer can be
limited using the potentiometer on the back panel. If you wish that the max. stirring speed be adjustable
through an RS command, the potentiometer is to be set to stage 9.

3 Sample plates of the TW alpha plus Titration Sample Changer

Four sample plates are available for the TW alpha plus Titration Sample Changer:
TZ 1452 sample plate: 12 samples
TZ 1459 sample plate: 16 samples
TZ 1454 sample plate: 24 samples
TZ 1444 sample plate: 24 samples
Sample plate : 48 samples
On the back panel of the TW alpha plus Titration Sample Changer there is a stage switch inscribed
ben/Samples" (please refer to fig. 1, item 4). This switch is used to communicate the sample plates used to the
TW alpha plus Titration Sample Changer. Using a small screw driver, this switch can be set to the correspond-
ing size.
Here is: 0 = 12 samples
1 = 16 samples
2 = 24 samples
4 = 48 samples
This setting can also be made via software using the appropriate commands from a connected computer or
titration device; please refer to chapter 7, "Command list of the TW alpha plus Titration Sample Changer".
The sample plates are set on clock-wise according to the mark engraved on the sample changer. The connec-
tion with the TW alpha plus Titration Sample Changer is made by simply placement on the corresponding driv-
250 ml low shape, 400 ml high shape
100 ml to 150 ml, high and low shape, 250 mm high shape
50 ml, high shape
COD reaction vessel according to DIN 38 409, Part 41
Available as a special version upon request.
"Pro-