Hanna Instruments PCA 310 - Manual (Page 45)

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For accurate calibration use two different beakers for each buffer
solution, the first one for rinsing the probe and the second one
for calibration. By doing this, contamination between buffers is
minimized.
Unscrew the probe from its position. Take care to stop the
sample flow before removing the probe. If necessary, discon-
nect the probe from analyzer to prevent the damage of the
probe cable.
ONE POINT CALIBRATION
Immerse the pH probe into the buffer solution
(e.g. pH 7.01) until the metal ring is immersed,
then stir gently.
Select the “pH Menu” - “Cal. pH Probe” - “Buffer
pH Cal.”.
• The analyzer will prompt to select the first buffer. Select the
buffer (e.g. pH 7.01) using “UP” or ”DOWN” arrow keys
and confirm.
• The analyzer checks
for readings stabil-
ity. During this pe-
riod, the “Wait for
stabilize” message
is displayed.
Note: If the read value, calculated with the default offset and slope, is
different from the expected value with more than 1.15 pH (i.e. offset
> 68mV), the “Wrong calib. values” message is displayed.
The message “Wrong calib. values” appears also if the pH
probe is defective or not connected. The problem could be
identified if the buffer set value is compared with the actual
read value (first and second line of the display).
If the probe is inserted in the appropriate buffer, the measur-
ing cycle is restarted automatically and message “Wait for
stabilize” is displayed again.
• If the temperature reading is wrong, the value is set to 25 °C
and a blinking “*” is displayed near it, indicating that is not
the real temperature value. The calibration procedure is not
interrupted.
• When the reading become stable, the analyzer displays
“Stable... press CFM”.
Buffer 1 pH: 7.01
Measured pH: 7.02
Temp. [ºC]: 25.1
Wait for stabilize
pH 7.01
Probe