Xylem FDO 925 - Manual (Page 10)

Maintenance, cleaning, replacement FDO
®
925
26 ba75898s01 04/2010
3.2 Exchanging the sensor cap
Note
Before removing the sensor cap, observe the general maintenance instruc-
tions in section 3.1.
To exchange the sensor cap, proceed as follows:
Removing the sen-
sor cap
Mounting the sen-
sor cap
1 Pull the sensor out of the sample.
2 Clean the outside of the sensor (see section 3.3.1).
3 Unscrew the fixing ring from the sensor by hand.
4 Thoroughly clean and dry the sensor head once again.
5 Grasp the sensor cap on the sides (arrows in figure on the left) and
remove it by pulling it away from the sensor in a straight upward
direction.
Caution:
Do not push any tools or other sharp objects between the sealing sur-
faces. This would damage the sealing surfaces and sealing ring.
6 Check the front surface of the sensor for absolute cleanness and
clean it if necessary (see section 3.3.2).
7 Thoroughly clean the thread of the fixing ring.
8 Check the sealing ring for intactness and correct position.
The sealing ring has to be replaced if it is damaged.
9 Aim the sensor head upwards and place the new sensor cap on the
sensor. The locking device on the sensor head must be inserted into
the receptacle on the inside of the sensor cap (see figure on the left).
10 Put the fixing ring on the sensor head and screw it tight by hand as
far as it will go. A gap of approx. 0.8 mm remains between the fixing
ring and sensor.
The sensor is immediately ready to measure.