Xylem FDO 925 - Manual (Page 7)

FDO
®
925 Measuring / Operation
23 ba75898s01 04/2010
2 Measuring / Operation
2.1 General information on the handling of the sensor cap
Despite its exterior robustness, the sensor is a high precision optical instru-
ment. Therefore, you should take the following precautions when dealing with
the FDO
®
925:
z Please do not touch the sensor membrane with your fingers
z Avoid any great mechanical stress of the sensor membrane (pressure,
scratches).
2.2 Commissioning
Scope of delivery z D.O. sensor FDO ®
925 with sensor cap
z Check and storage vessel, FDO ®
Check
z Operating manual
Preparing the sen-
sor for measure-
ment
Connect the sensor to the measuring instrument. The sensor is immediately
ready to measure.
2.3 Measuring
Minimum immer-
sion depth
Observe the required minimum immersion depth (see chapter 5 T ECHNICAL
DATA ).
Indicent flow The FDO
®
925 D.O. sensor enables precise measurements without any
incident flow.
However, an incident flow of the sensor membrane improves the responding
behavior of the sensor (see chapter 5 T
ECHNICAL DATA ). The incident flow can
be provided in different ways, e. g.:
z The flow of the water to be measured is sufficient (aeration tank, water
pipe, stream)
z Slowly pull the sensor through the water by hand (lake, container), or
z Use a flow aid such as a magnetic stirrer with stirring device (see
chapter 6 W EAR PARTS AND ACCESSORIES )