Xylem YSI ProDSS, User Manual

Page: 73 / 92

71
Maintenance and Storage
Figure 81
pH - pH/ORP sensor module
replacement
ProDSS sensor module replacement
ProDSS pH, pH/ORP, ammonium, chloride and nitrate sensors feature replaceable sensor modules. These modules can
be replaced by the user as needed. Typical working life of a pH or pH/ORP sensor module is 18 to 24 months. Typical
working life of ammonium, chloride and nitrate sensor modules is 4 to 8 months.
Perform the pH - pH/ORP and ISE sensor module replacement in a clean, dry laboratory environment.
Module Replacement
1.
Peel off and discard the sticker that covers the junction of the
sensor body and the module (
Figure 81 ).
2. With a small, flat-blade screwdriver, carefully remove the small
rubber plug from the gap in the hard plastic ring at the base of the
sensor module.
3. Using two fingers, squeeze the sensor module’s hard plastic ring
so that it compresses the gap left by the rubber plug.
4. Steadily pull the sensor module straight from the sensor body,
rocking slightly if necessary.
NOTICE: The o-ring is unusable after removal from the sensor
body. Do not reinstall the removed sensor module or
o-ring after removal. Dispose of the module according
to you organization’s guidelines or return it to YSI for
recycling (
“Service information” on page 83 ).
5. Inspect the sensor connector port for debris or moisture.
If detected, remove it with lint-free cloth or a light blast of
compressed air.
6.
Visually inspect the two new o-rings for nicks, tears, contaminants
or particles. Discard damaged o-rings.
7. Without twisting, carefully install the new o-rings over the threads
and into the o-ring grooves.
8. Apply a thin coat of o-ring lubricant to the o-rings only. Wipe any
excess from the threads and sensor module.
NOTICE:
If a sensor module is removed for any reason, the o-rings
must be replaced.
9. Align the prongs on the base of the sensor module with the slots
in the sensor body. The sensor module is keyed to insert in only
one orientation.
10. Push the sensor module firmly into position until it clicks. Wipe any
excess o-ring lubricant from the assembled components.
11.
Wrap the junction of the sensor module and sensor body with the
new sticker included in the sensor module kit. The sticker helps
keep the sensor module junction clean and retain the rubber plug
throughout deployment.
12. Write the replacement date on the sticker.
13. Calibrate the sensor ( “pH/ORP” on page 39 or “ISE calibration
3-point on page 51 ).