Xylem WTW Multi 3430, Operating Manual

Page: 71 / 134

Operation
Multi 3430
71
ba75865e19 04/2015
Evaluation The evaluation is based on the accuracy required by the user. Together
with the nominal value (100 %), this results in a validity scope for the
check.
If the measured value is within the validity scope, no cleaning or user
calibration is required.
If the measured value is outside the validity scope, the sensor shaft and
membrane should be cleaned, and the check should then be repeated.
Example:
– Required accuracy: ± 2 %.
– In water vapor-saturated air or air-saturated water, the nominal
value for the relative D.O. saturation (abbreviated: saturation) is
100 %.
– Therefore, the validity scope is 98 ... 102 %
– The check resulted in a measured value of 99,3 %
The measurement error is within the specified validity scope.
No cleaning or user calibration is required.
4 Start the measurement with <MENU/ENTER> .
The measured value is checked for stability (stability control).
The [AR] status indicator is displayed. The measured parame-
ter flashes.
5 Wait for the AutoRead measurement to be completed
([HOLD][AR]) display or
accept the measured value with
<MENU/ENTER> .
The measured value is frozen.
6 Switch to the measured value display with <M> .
The check measurement is not documented.