Measuring The Ph Value - wtw inoLab pH 720 Operating Manual

pH 720
AutoRead AR
(Drift control)

4.2.1 Measuring the pH value

1 Perform the preparatory activities according to sec-
tion 4.2.
2 Immerse the pH electrode into the test sample.
m
3 Press the
play. The pH value appears on the display.
The AutoRead function (drift control) checks the stability of
the measurement signal. The stability has a considerable ef-
fect on the reproducibility of the measured values.
For identical measurement conditions, the following criteria
apply:
l
pH value: better than 0.02 (setting time: > 30 s)
1 Call up the pH measuring mode by pressing
2 Activate the AutoRead function by pressing
The current measured value is frozen (Hold function).
3 Start the AutoRead function by pressing
AR flashes on the display until a stable measured val-
ue is reached.
4 If necessary, start the next AutoRead measurement
by pressing
5 To terminate the AutoRead function: Press the
key.
key until pH appears in the status dis-
g
.
Operation
m
.
a
.
g
.
a
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