OEM OPM223, Operating Instructions Manual, Page: 40 / 104

Operation OPM223/253
40
Check
The CHECK function group is only available for devices with a Plus Package.
In the CHECK function group, you can select two different monitoring functions for the
measurement:
SCS electrode monitoring
The Sensor Check System monitors the pH and reference electrode for incorrect
measurement and complete failure.
SCS identifies the following reasons for incorrect measurement:
• Electrode glass breakage
• Fine short circuits in the pH measuring circuit, also e.g. moisture or dirt bridges at terminal
points
• Contamination or clogging of the reference electrode
• Leak current for ISFET sensor
The following three monitoring methods are used:
• Monitoring the pH electrode for high resistance (alarm if a minimum impedance is undershot,
approx. 500 k
Ω
).
This function cannot be selected for antimony and ISFET electrodes (A4).
• Monitoring of impedance of the reference electrode (alarm if set threshold value overshot).
This function can only be selected for symmetrically high-resistance measurement.
• Monitoring of leak current for ISFET sensors (pre-alert E168 at I
LEAK
> 200 nA, error E008 at
I
LEAK
> 400 nA).
F7
Set error current to
be effective for the
selected error
no
yes
The option selected in F4 is effective or
ineffective in the event of an error.
This setting
only applies to the error
selected in F5.
F8
Automatic cleaning
function start no
yes
This field is not available for certain
errors, see "Trouble-shooting and fault
elimination" section.
F9
Select return to
menu or next error next = next error
←
R
If
←
R is selected, you return to F, if next
is selected, you go to F5.
Coding Field Setting range
(Factory settings, bold) Display Info
F7
Curr . Assg
no
F8
CleanTrig
no
F9
Select
next