IPS Controllers M920 Owner's Manual page 29

M920 & M920W pH/Dual ORP Controller Owner's Manual
h. Turn on the M920 controller.
i. Open the flow cell valves and wait for a few minutes for the
system to stabilize and get an accurate reading. Adjust the Set
Level if necessary.
3. Checking the ORP sensor
a. Place the sensor in a cup of tap water. The reading should
gradually drop down to 400mV.
b. Add a pinch of Dichlor, Trichlor or a drop of Liquid Chlorine into
the water. The reading should increase above 750mV.
4. Checking the pH sensor
a. Place the sensor in a cup of tap water.
b. Add a small amount of acid to the water and take a reading. It
should show a low number (probably 6.0).
c. Rinse the sensor, then place into a solution that is higher than
7.5pH. Verify that the reading is increasing.
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