Thermo Scientific ALPHA PH 560 Manual page 26

Thermo Scientific Alpha pH 560
Figure 4–18. NIST Buffer 2-Point Calibration
From pH measurement mode press CAL key to enter
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calibration mode as described in page 16. The LCD shows
'CAL PH'. Press ENT key to begin first calibration point.
Place the electrode in pH 6.86 buffer. Immerse the
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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 ENT key to confirm the reading.
The pH Controller moves to the second calibration point.
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The lower display shows next standard buffer value (pH
4.01). Use ▲ and ▼ keys to select your second buffer
from one of the preset values: pH 4.01 or 1.68 or 9.18 or
12.45. Remove the electrode from the first buffer, rinse and
then immerse it into the second buffer. Allow the reading to
stabilize. LCD shows 'READY' annunciator when the
reading is stable.
Press ENT key (or CAL key) to confirm the reading.
The calibration is completed. The pH Controller re-
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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.
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