Metrohm 726 Titroprocessor - Manual (Page 188)

8.9 CAL
726 Titroprocessor, Instructions for use 182 182
The simplest form of an automatic calibration loop could look like this:
Command Parameters Parameters
ДДДДДДДДДДДДД ДДДДДДДДДДДДДДДДДДДДДДДД ДДДДДДДДДДДДДДДДДДДДДДДД
(CAL
(CASE $BC = 1
MOVE_B Special beaker Buffer 7 to Tower 1
CASE $BC = 2
MOVE_B Special beaker Buffer 4 to Tower 1
)CASE
LIFT on Tower 1 to position work mm
STIR_C Address 1 Stirring rate 6
CAL* pH Sensor calibration
Sensor comb. glass Signal drift 2 mV/min
Meas. input A1 Equilibr.time auto s
Temperature 25.0 øC
STIR_C Address 1 Stirring rate off
LIFT on Tower 1 to position shift mm
...
)CAL
The precondition for this type of automatic calibration is that the special
beaker positions (with the corresponding names) of the sample rack used
have been correctly configured.
On the flash card supplied with the 726 Titroprocessor you will find a
method (SC_CAL.mth) in which the automatic calibration is completely
programmed as the start sequence for a series of titrations. You only need
to complete it with a titration mode and to enter the buffers to be used (in
CAL* mode). Do not forget to define the required special beakers for the
sample rack to be used.
Behavior if calibration problems occur
If during an automatic calibration a calibration error occurs and the run is
not interrupted the following automatic procedures are provided:
• If a buffer cannot be properly measured then this buffer will not be taken
into account for the calibration. The calibration will nevertheless be con-
tinued. A corresponding error message will appear in the result report.
• If at least two buffers can be properly measured then these values will be
used for the calibration. The method will be continued.
• If only one buffer or no buffer at all can be properly measured the cali-
bration will be interrupted with an error message. You must then decide
whether the method should nevertheless be continued or terminated. In
the first case standard calibration data (pH
as
7.000, slope 1.000) will be
assumed.