Malvern MPT-2, User Manual, Page: 59 / 85

Maintenance Chapter 5
MPT-2 & Degasser Page 5-3
Note
Pumping air into the tubing prior to the cleaning fluid will aid the clean-
ing. This will act as a buffer, first driving the sample through the tubing
before the cleaning fluid cleans the tubes. This is simply done by removing
the cleaning fluid while leaving the pump running.
Cleaning the Titrant tubes
The titrant tubes can also be cleaned using the same tab. Simply insert containers of
cleaning fluid in place of the titrant containers. - refer to the connection prep chap-
ter
Maintaining the pH probe
The pH probe is essential to ensure good performance of the Titrator, and its
maintenance is of paramount importance. As with any pH probe, its performance
will degrade over time and will eventually have to be replaced. The frequency of
replacement will be determined by; the maintenance of the probe, how frequently
it is used and the types of sample being measured. In this respect a pH probe can be
thought of as a "Consumable" item. Malvern recommends that the probe is
replaced every year, but this frequency may vary.
Note three important points when using a pH probe:
6.
The performance of the pH probe will be severely affected if it is allowed to
dry out (even for short periods).
7.
The pH probe should be calibrated at regular intervals.
8.
The probe should be cleaned regularly - If the probe responds slowly a message
to clean the electrode will be given.
This electrode operates over a range of pH 1 to pH 14, and temperature range of 0
to 70°C, though it is recommended that the titrations are performed at ambient
temperature conditions, i.e. by setting the measurement temperature to equal the
ambient temperature.
This is for two reasons:
1.
The pH Probe is not temperature compensated, so the sample in the container
must be the same temperature as the cell.
2.
At higher temperatures the operating life of the pH probe will be greatly
reduced.
MAN0318-4.0 - MPT-2 Autotitrator-Degasser.book Page 3 Tuesday, September 4, 2012 12:15 PM