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CALIBRA
TION
9.3. RELATIVE mV CALIBRATION
1. Press
CAL
when the instrument is in relative mV measurement mode. The relative mV value and
the temperature value are displayed.
2. Press the / keys to modify displayed relative mV value.
3. When the reading is stable and the Relative mV offset is inside the offset window (±2000 mV),
CFM
functional key is displayed.
4. Press
CFM
to confirm. The instrument returns to measurement mode.
5. If the absolute mV reading is out of range or the Relative mV offset is out of the offset window,
“Wrong relative offset” message is displayed.
Change the input value or the Relative mV value to complete the calibration process.
9.4. ISE CALIBRATION
It is recommended to calibrate the instrument frequently, especially if high accuracy is required.
The ISE range should be recalibrated:
• whenever the ISE probe or ion charge is changed,
• at least once a week,
• after testing aggressive chemicals,
• when calibration alarm time out is expired - “CAL DUE” tag blinks (if enabled).
The ISE electrode requires conditioning so it must be kept immersed a few seconds to stabilize.