Running A Multi-Point Ph/Ion Calibration - Mettler Toledo SevenGo Duo pro pH/ORP/Ion/Conductivity meter SG78 Mode D'emploi

b) Press
The softkeys change back to
c) Navigate to a cell and press Delete to remove a value.
d) To finish editing the table, navigate with the
e) Press READ to confirm the action and exit the menu.
4.8 Calibration
The SevenGo Duo pro™ pH/Conductivity meter allows you to perform pH calibrations with up to 5
points.
4.8.1 Running a one-point pH/ion or one-point conductivity calibration
a) Press and hold MODE for 3 seconds to switch to single channel pH or single channel conductivity
mea sure ment screen when in dual channel measurement.
b) Place the electrode in a calibration buffer/standard and press CAL.
Cal 1 appears on the display for pH and ion; CAL appears on the display for conductivity.
c) The meter endpoints according to the preselected endpoint mode after the signal has stabilized or af-
ter pressing READ.
The relevant buffer/standard value is shown on the display.
For the conductivity calibration, the result is shown directly on the display.
d) Press End to accept the calibration.
The calibration result (offset and slope for pH, cell constant for conductivity) is shown on the
dis play.
e) Press Save to save the result.
— or —
f) Press MODE/EXIT to reject the calibration and return to sample measurement.
Notes
●
With the one-point calibration only the offset is adjusted. If the sensor was previously calibrated
with a multipoint calibration the previously stored slope will remain. Otherwise the theoretical slope
(-59.16mV/pH) will be used.
●
The second point required for the conductivity calibration curve is permanently programmed in the
meter and is 0 S/m for a specific resistivity moving toward infinity. To ensure the most accurate con-
duc tiv i ty readings, verify the cell constant with a standard solution regularly and recalibrate if nec es-
sary.

4.8.2 Running a multi-point pH/ion calibration

pH and ion calibrations can be run with this meter for up to 5 points.
a) Run the calibration as described in "Running a one-point pH/ion or one-point conductivity cal i bra-
tion" (steps a - c).
b) Rinse the electrode with deionized water.
c) Place the electrode in the next calibration buffer.
d) Press CAL.
Cal 2 appears on the display. The meter endpoints according to the preselected endpoint mode
after the signal has stabilized or after pressing READ. The relevant buffer value is shown on the
dis play.
e) Repeat the steps b - d for all calibration buffers.
Press End to end the calibration procedure.
f)
pH/ORP/Ion/Conductivity meter SG78
and to enter the value and press READ to confirm.
and
Operating the pH/ORP/Ion/Conductivity meter SG78
.
and to highlight Save.
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