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C. Checking the ORP Sensor
1.
The ORP sensor should be checked every six months or
anytime the feeder oversanitizes the water.
2.
Clean the sensor tip as noted previously.
3.
Place the sensor in a clean glass of tap water. This should
give a reading between 200 and 400 mV. Adding a small
amount of chlorine should cause the ORP level to jump to
between 700 and 800 mV.
If the sensor has been sitting in a high concentration of
chlorine for more than 20 hours, it may pick up a ‘memory’.
that will not allow it to read below the 500 to 600 mV level.
If this is the case, adjust your controller setting accordingly.
The sensor should return to normal after a week or two
of normal operation. To return it to normal functioning more
quickly, place the sensor in a glass of tap water for
72 hours.
4.
If the sensor does not respond as indicated, the sensor
should be replaced.
D. Checking the pH Sensor
1.
The pH sensor should be checked every six months or
anytime the pH goes out of range or cannot be calibrated to
the test kit.
2.
Place the sensor in a clean glass of tap water. Add a small
amount of acid to the glass. The pH reading should drop to
the lowest red light. Then place the sensor in any solution
with a pH above 7.5. The pH reading should move up.
3.
If the sensor does not respond as indicated, the sensor
should be replaced.