Metex 8760CLP Total Free Chlorine & pH Analyzer - Manual (Page 28)

AQUAMETRIX INC.
1-800-742-1413 www.aquametrix.com
28
Monthly Maintenance
Certain applications may require occasional sensor cleaning. A monthly maintenance check is
recommended by visual examination of the sensor cell area. If needed, a soft wipe can be used to blot,
plus detergent and water to remove any deposits. Rinse thoroughly after cleaning with water. Run a
calibration and return to service if sensor efficiency is above 50 percent..
White silt inside the sensor cap may not cause problems. However, if after calibration the sensor
response is slow, replace the electrolyte and wipe the coils and surface lightly using a soft wipe, or a
little more vigorous cleaning can be done using a toothbrush. Recharge with fresh electrolyte. Calibrate
and return the sensor to service.
Semi-Annual Maintenance
Replace the membrane, P/N AM-A2104036, and electrolyte solution, P/N AM-A1100239, following the
appropriate membrane replacement procedure in Assembly of the Chlorine Sensor section in Chlorine
Sensor Instructions. Examine the coils for any discoloration or heavy coating. Such coatings should be
removed for best performance (caution the silver coils are soft metal, never use force in cleaning). To
clean the coils, refer to the Chemical Cleaning section for further instructions.
Remove the old membrane from the cell and replace with a new one. Re-assemble the cell, calibrate,
check efficiency and if above 50 percent, place in service.
Chemical Cleaning
Chlorine sensors can be refreshed with AquaMetrix P/N AM-A1100227, chlorine sensor renew solution.
This solution is only available in 30 mL bottles. Due to the acidic nature of this solution, the 30 mL
bottle is packaged in a baking soda packer for non-hazardous shipment.
NOTE: This procedure should be done over a sink. Wear plastic or rubber gloves and protective eye-
wear as the solution is acidic. Wash hands thoroughly with lots of water if the solution comes in contact
with the skin.
1. Disassemble the chlorine sensor to expose the silver coils and gold tip.
2. Immerse in cleaning solution as shown in illustration 24
for about 10 minutes, or until deposits disappear.
3. Remove and rinse in distilled or deionized water; use a
small toothbrush to scrub coils to speed removal, if
necessary.
4. Repeat steps 2 and 3 until coils and tip look clean and have
a shine; re-assemble chlorine sensor with new membrane
and fill solution, calibrate and verify efficiency is above
50%.
5. Repeat steps 2 to 4 as necessary to get at least 50%
efficiency. If not possible, the chlorine sensor should be
replaced.
Illustration 24: Chemical cleaning