User Guide

17
ing message “time-out”, then shows “WRONG” and it is not
possible to complete calibration.
• At the end of calibration, with the meter set as pH control-
ler, the instrument checks if the offset is between -30 and
30 mV and the slope between 53.5 and 62 mV/pH. If the
values are not within these ranges, the message “OLd
ProbE” scrolls twice across the LCD. The electrode is still
working, but it is necessary to perform a cleaning proce-
dure (see “Electrode conditioning and maintenance” and
“In-line Cleaning” sections) or replace it.
If the offset is outside the -60 to 60 mV range, the “dEAd
ProbE” message will scroll across the LCD and the corre-
sponding error is activated. The electrode has to be replaced
as soon as possible because there is no reliability on the
measured pH values.
One-point calibration with manual selection of the calibration value.
A one-point calibration at a value different from the standard
buffer values is possible by entering the desired calibration
value. This is the actual pH value at the current calibration
temperature.
• Enter the pH calibration mode (no matter if
the standard or NIST buffer set is selected),
then press (ALT+) SETUP while the second-
ary LCD is displaying the first buffer value
(pH 7.01 or pH 6.86).
• The pH calibration value will switch
to 7.00, the first digit starts blinking
and it is possible to change its value
simply using the  or  key.
• Once selected the first digit value, press the  key: the first
digit will be fixed and the second one will start blinking.
Pressing of the  key repeatedly will result on circularly
moving on the secondary LCD.
• When the desired calibration value is reached (must be
within 0.00 to 16.00 pH), press the CFM key to confirm
and the calibration will proceed as described above.
• If the selected value is outside boundaries, the confirma-
tion is not accepted and the first digit keeps blinking (waiting
for confirmation of a valid value).