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Maintenance Chapter 5
MPT-2 & Degasser Page 5-7
tinuing. (After a pH calibration has finished, pH probe output (mV) will
change to pH probe output from calibration (mV) .
6.
When the calibration of the first pH point is complete, the pH point will show
a
alongside.
7.
Remove the probe from the first pH buffer, rinse with deionised water and dab
dry.
8.
Continue the calibration until all required pH points have been calibrated.
During the calibration a progress bar at the bottom of the dialogue indicates how
far the calibration routine has proceeded.
The ticks or crosses alongside the pH probe indicate the following:
Points can be deleted by selecting the point and pressing Remove .
Choosing the buffers when calibrating
The default buffers for calibrating are pH 4 and pH 9. Other values may be used
but ensure that the lowest and highest values are at least 3 pH values apart. Also if
all titration measurements tend to be in the lower end of the pH table it is advisable
to use pH 2 and pH 5 buffers to calibrate the probe.
Adding a pH buffer point
To use a different pH value, a new pH buffer point must be added to the selection
list. Press
Add to display the Calibration point dialogue, then perform either of
the below actions:
1.
Select a defined pH point from the Calibration pH list and press OK to add it
to the Calibration points list in the main dialogue.
2.
Or if using a pH buffer not available in the list, select Custom , type the
value in the Custom buffer entry box, then press OK to add it to the Cali-
bration points list in the main dialogue.
If the maximum accuracy of calibration is required over a wide pH range, then 3 or
4 buffers should be used
The pH probe for the Titrator is supplied with sachets of pH4 and pH9 buffers.
Follow the instructions supplied with the sachets for the best methods of making
the buffer solutions.
A pH point has been chosen but not yet calibrated.
A pH point has been chosen and been calibrated.
Calibration points selected during a previous calibration, which have not
been calibrated during the current session. If required select these points
and perform the calibration process as described. A tick will appear once
it is complete.
MAN0318-4.0 - MPT-2 Autotitrator-Degasser.book Page 7 Tuesday, September 4, 2012 12:15 PM