+GF+ Signet 4630 Operating Instructions Manual page 37

Appendix
Storage of sensor
• Remove the membrane cap and internal electrolyte
solution.
• Rinse the sensor internal chamber with DI water or cold
tap water; drain and allow to dry.
• Place the membrane cap back onto the sensor. INSTALL
LOOSE, DO NOT COMPLETELY TIGHTEN THE CAP.
WHEN STORED DRY, THE MEMBRANE CAP MUST BE
STORED RELAXED AND UNSTRESSED.
• Store sensor DRY in the shipping bottle,
DO NOT ADD WATER.
Storage Periods Greater than 1 week,
but less than 2 months:
Recommissioning Procedure:
1. Fill the sensor with the electrolyte as outlined in
Maintenance, Page 36, and install the membrane cap.
2. The sensor will have to be polarized in the fl ow cell with
fl owing Chlorinated water before being used.
Note: This may take 30 to 120 minutes before calibration
can be performed.
3. If the sensor does not recover after recommission, follow
steps 1-10 outlined under Storage periods greater than
2 months.
4. If the sensor still fails to work properly, continue with
steps 11-17.
CAUTION!
Bleach and Chlorine Dioxide solutions are very
corrosive and may release dangerous gases if it
comes in contact with acids.
• Wear proper protective clothing (gloves and eye protection)
• Avoid contact with skin and eyes
• Observe all warnings on safety data sheets
• Avoid spilling bleach and possible contact with acids
Curved Surface
Figure 1
Figure 2
Storage periods greater than 2 months:
• If the sensor has been in storage for a long period of
time, or used in a chlorine free environment, the sensor
may develop a low slope (output), which may cause the
sensor to have a slow response time.
• In this case, the sensor must be reconditioned.
Required to recondition a sensor:
• DI Water
• Beaker (any size available)
• Polishing Sheets (Included in sensor maintenance kit)
• Free Chlorine: Chlorine Bleach (13% concentration)
• Chlorine Dioxide: Aqueous Chlorine Dioxide solution
Reconditioning Procedure:
1. Remove the sensor from the 2750-7 electronics.
2. Remove the membrane cap.
3. Place the sensor on a fi rm fl at surface with the gold
cathode pointing upward.
4. Apply a small amount of water to the Blue (Coarse)
polishing paper (dull side).
5. Polish the gold electrode by moving the paper in a
circular pattern for 10 seconds. DO NOT go back and
forth in a single direction. See Figure 1.
6. Rinse the sensor tip with DI water.
7. Apply a small amount of DI water to the White
(Fine) polishing paper (dull side) and polish the gold
electrode by moving the paper in a circular pattern
40-60 seconds. DO NOT go back and forth in a single
direction. See fi gure 1.
8. Rinse the sensor tip with DI water.
9. Top off the sensor with electrolyte and inspect
membrane for dirt or damage. Replace if necessary.
10. Insert the sensor into the 2650 electronics and
apply power.
11. Fill beaker with a 12 mm (½ inch) of the appropriate solution.
12. Position or suspend the sensor 0.2 mm to 12 mm
(¼ in. to ½ in.) above the appropriate solution.
See Figure 2. DO NOT SUBMERGE THE SENSOR.
13. Apply power to the system.
14. Monitor the nA of the sensor (press the down arrow
once on the 8630 transmitter). The nA reading should
start to rise. Response time and nA reading will depend
upon the temperature of the appropriate solution.
15. Once the sensor's nA reading reaches approximately
300-360 nA allow the sensor to remain in the beaker,
suspended over the appropriate solution, for an
additional 20 minutes.
• If sensor does not recover quickly, cover the
beaker to avoid air contamination.
• Contact the factory for assistance (www.gfsignet.com).
16. After 20 minutes, remove the sensor and install it into
the fl ow cell and restore fl ow to the system.
17. Calibrate the sensor after the system has become stable.
463X Chlorine Systems Manual
37