wtw inoLab pH 720, Operating Manual, Page: 17 / 48

pH 720 Operation
17
4.2.1 Measuring the pH value
AutoRead AR
(Drift control)
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:

pH value: better than 0.02 (setting time: > 30 s)
1 Perform the preparatory activities according to sec-
tion 4.2.
2 Immerse the pH electrode into the test sample.
3 Press the
m
key until pH appears in the status dis-
play. The pH value appears on the display.
1 Call up the pH measuring mode by pressing
m
.
2 Activate the AutoRead function by pressing
a
.
The current measured value is frozen (Hold function).
3 Start the AutoRead function by pressing
g
.
AR flashes on the display until a stable measured val-
ue is reached.
4 If necessary, start the next AutoRead measurement
by pressing
g
.
5 To terminate the AutoRead function: Press the
a
key.