Parameter Settings (Ph Only); Checking The Orp Probe (Redox Only) - ProMinent DULCOMETER DMT Series Operating Instructions Manual

7.1.3 Parameter settings (pH only)

pH
param. measurement
zero point = -0.1 mV
slope = 60.30 mV/pH
probe check: on
The following settings options are available to you:
Zero point
and slope
Probe check
If the probe check is active (on flashes) the resistance value of the pH
probe is displayed under "resistance".
If the resistance value falls below 2 MΩ at any time during operation for
longer than 1 minute the error message "defective pH probe !!" appears in
the permanent display. Alternatively, if it is above 200 MΩ and the
measurement signal is fluctuating significantly, the error message "pH input
error!" is activated along with the display value "-2.00 pH" or "16.00 pH".

7.1.4 Checking the ORP probe (redox only)

Redox
checking ORP-probe
ProMinent ®
Enter the calibration values of the pH probe under "zero point" and
"slope" if these have been obtained by other means than via the DMT
calibration menu.
The current pH value is displayed under "meas. value" for monitoring
purposes.
Select on or off under "probe check" to activate/deactivate the pH
probe check.
NOTE
Sample liquid temperatures below 20 °C or above 60 °C can
cause incorrect signals during probe monitoring. In this case
we recommend that you switch off the probe check as long as
the pH probe is functioning correctly.
NOTE
The output current value is frozen during probe testing at,
depending upon the general settings, the last measured value
(HOLD) or at 23 mA (see chapter 7.1.7 General settings).
zero point = -0.1 mV
slope = 60.30 mV/pH
probe check: on
meas. val. = 7.12 pH
or
zero point = -0.1 mV
slope = 60.30 mV/pH
probe check: on
resistance = 1.23 MΩ
probe in buffer!
faulty probe!!
buffer value: 465 mV
meas. value: 509 mV
DMT settings
check dry probe
resistance = 1.23 MΩ
allowed > 2 MΩ
faulty probe !!
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