Xylem Multi 3420 - Manual (Page 72)

Operation Multi 3420
72 ba75864e11 02/2011
4.9.4 FDO
®
Check procedure (check of the FDO
®
925)
Why should you check
the sensor?
With the FDO
®
Check procedure, you can find out in a simple manner
whether the FDO
®
925 D.O. sensor should be cleaned or calibrated.
When should you check
the sensor?
Checking can be useful in the following cases:
z When the check interval has expired
z If the measured values seem to be implausible
z If you assume that the sensor cap is contaminated or at the end of
its lifetime
z After the sensor cap was exchanged
z Routinely within the scope of company quality assurance measures.
FDO
®
Check procedure Check in water vapor-saturated air.
Use the check and storage vessel (FDO
®
Check) to carry out the FDO
®
Check procedure.
Stability control
(AutoRead)
The Stability control function (AutoRead) is automatically activated for
the FDO
®
Check.
Carrying out the FDO
®
Check procedure
Proceed as follows to carry out the FDO
®
Check procedure:
Note
The sponge in the check and storage vessel must be moist (not wet).
Leave the sensor in the check and storage vessel long enough so it can
adapt to the ambient temperature.
1 Connect the D.O. sensor to the meter.
2 Place the D.O. sensor in the check and storage vessel, FDO
®
Check.
3 In the measuring menu, start the FDO
®
Check procedure with
FDO Check / Start FDO Check.
The meter switches to the measured parameter, %.