Thermo Fisher Scientific Alpha pH 550 - Manual (Page 24)

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1-Point Calibration:
CAL
HOLD
ENT
CAL
pH READY
HOLD
pH
CAL
CAL mV
pH
HOLD
MEAS
PH
°C
ATC
READY ENT
1 2 3 4
1 1
From pH measurement mode press CAL key to enter calibration mode as
described in section 4.2. The LCD shows ‘CAL PH’. Press ENT key to
begin calibration.
2
Place the electrode in pH 6.86 buffer. Immerse the temperature probe in the
buffer solution if ATC mode is enabled. Immerse the potential matching pin
in the buffer if symmetrical mode is enabled. The buffer annunciator
appears in LCD. Lower display shows pH 6.86 (NIST standard buffer).
Upper display shows the current uncalibrated pH reading. Allow the reading
to stabilize. LCD shows ‘READY’ annunciator when the reading is stable.
Press CAL key to confirm the reading.
3
The calibration is completed. The pH Monitor re-calculates electrode
properties based on the calibration. The new slope (in mV) is shown in the
upper display and pH reading at 0mV (pH7.00
± offset) is shown in the
lower display.
Press ENT key to exit from the calibration.
4
The pH Monitor reverts to pH measurement mode.
2-Point Calibration:
CAL
ENT
CAL mV
pH
ENT
1 2 4
CAL
pH READY
pH
CAL
pH READY
pH
ENT
CAL
pH
READY
pH
CAL
pH READY
pH
CAL
pH READY
pH
3
3
3
3
MEAS
PH
°C
ATC
READY
5
ENT
CAL
ENT
CAL
ENT
CAL
ENT
CAL