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Introduction and hardware Chapter 1
MPT-2 & Degasser Page 1-7
The sample container initially just contains the sample to be measured. Titrants are
added to the sample through the titrant tubes and the dispersion is stirred.
Two sizes of containers can be used; the 'standard' container as shown above, and a
'large volume' container, which will generally be used for dilution titrations.
To attach and remove the 'standard' sample container, simply screw the container
into, or unscrew the container from, the dispersion unit; as shown above.
Instructions on fitting the large volume container are described in the Titrants
SOP dialogue section in the next chapter.
Be careful not to splash any sample when inserting and removing the sample con-
tainer.
The sample containers are disposable - replacement containers can be obtained
directly from Malvern instruments.
Note
This manual will assume that a standard sample container will always be
used, unless otherwise stated.

pH probe
The pH probe measures the pH of the sample. The performance of the pH probe
will deteriorate over time, though correct maintenance will extend its life and
ensure rapid and accurate titrations. It is recommended that the probe is replaced at
least once a year.
Caution!
The probe must never be allowed to dry out. If it does it may need replac-
ing. See
Chapter 5 for details on maintaining the probe.

Magnetic Stirrer
The stirrer agitates the sample and aids titrant dispersion.
The stirrer motor is pulled forward from the front of the titrator to sit directly
below the sample container. A
magnetic stirrer 'flea' placed in the sample con-
tainer will agitate the sample once the stirrer is turned on during a titration or pH
calibration.
The speed of the stirrer is set through the Titrants SOP dialogue. The optimum
speed will depend upon the type of sample being titrated. Care should be taken
when adjusting the stirrer speed as air may be introduced into the sample. If in
doubt, set the stir speed check box to
Automatic .
MAN0318-4.0 - MPT-2 Autotitrator-Degasser.book Page 7 Tuesday, September 4, 2012 12:15 PM