11.3
Calibration statistics / calibration history
You can tell when pH electrodes are
beginning to age when they start deviating
from the calibrated zero point increasingly
fast and when there is a deterioration in slope.
A chronological record of the calibration data
is therefore advisable, so that the current
quality of an electrode can be determined.
The measuring transmitter Mycom CPM 152
includes two automatic record-keeping
facilities to simplify the assessment of
electrode aging in the menu points
“Diagnostics – calibration statistics” and
“– calibration history”.
Caution:
Not only the calibration statistics
but also the calibration history are
deleted completely when the
operating mode is changed or when
the instrument is reset to factory
settings!
11.3.1 Calibration statistics
The results of the last five calibrations are
stored in the calibration statistics in
chronological order. The nature of the entries
depends on the operating mode chosen
(pH, redox absolute or redox relative).
In the pH operating mode, the electrode zero
point and slope and the relevant calibration
date are displayed in two successive
windows.
The windows for the values of the second
electrode are then displayed in the case of
two-circuit measurement.
You can always move on to the next window
by pressing the E key.
In the redox absolute and redox relative
operating modes, only one window is needed
per electrode to display the electrode offset
and the relevant calibration date.
11.3.2 Calibration history
The following information is recorded for the
last five calibrations in the calibration history:
• Type of calibration
• Date and time
• Buffer and duration of the measurement
(except in the case of the data input
calibration)
You can scroll forwards and backwards be-
tween entries by pressing the
↑
and
↓
keys. In
the case of two-curcuit measurement, you
can move on to the window for the calibration
history of the second electrode by pressing
the E key.
Note:
Faulty calibrations are not included
in the calibration history.
The buffer value at 25 °C is entered
in the calibration types specified
buffers and calibration with
automatic buffer identification.
pm152e11.chp
mycom CPM 152
Diagnostics
Hauser
79
