Calibration
71
EN
•
It is essential that you use a dedicated,
clean container for each calibration value.
Do not use the same container under any
circumstances!
•
Clean the glass bulb following each calibra-
tion procedure (pH4, pH 7, pH 10) in a dedi-
cated container filled with clean water! Do
not use the same container under any cir-
cumstances!
11.1.1 Calibrating pH 7
We recommend that you first calibrate the neu-
tral measuring point (pH 7).
•
Power on the Wöhler WA 335.
•
Immerse the pH glass bulb fully in the cali-
bration solution pH7.
•
Stir carefully for approx. 1 min. ensuring you
do not create any bubbles.
Fig. 56: pH7 calibration solution
•
To enter the calibration mode press and
hold the CAL key for approx. 2 seconds.
•
As soon as the device recognizes the cali-
bration solution “CAL” and a measurement
value, for example “7.01”, begin to flash in
the display
•
If the displayed value deviates from the
setpoint value, use the arrow keys to set the
value to 7.00.
Fig. 57: Calibration value saved
SA is displayed after 30 seconds or when the
Enter key is pressed. The calibration value is
now saved.
•
Clean the glass bulb in a clean container
containing clean water.
11.1.2 Calibrating
pH 4 and pH 10
•
Proceed as described in point 11.1.1.
•
To store the probe when you have complet-
ed the calibration procedures, fill the trans-
parent protective cap with KCI electrolyte
storage solution (3 mol/l) and then screw it
onto the probe.
