USF Wallace & Tiernan DEPOLOX 4, Manual

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Basic set-up (Redox amplifier without PID controller)
MENU
Range zero point ZRO 400 mV F
Range final value RGE 900 mV F
Code 904 P
Setpoint (control contact) 700 mV P
Control direction INCR. P
HI alarm set 900 mV P
LO alarm set 400 mV P
Limit value time delay 0.00 min P
Hysteresis 3 mV P
Alarm relay N.O. P
mA output signal 0-20 mA P
10.3 MAINTENANCE OF THE REDOX PROBE
Depending on the degree of contamination of the sample water, the Redox probe should
be cleaned in regular intervals (see maintenance of pH probe).
A contaminated probe will respond sluggishly as indicated by an almost straight line
on the recorder tape. Often the indicated Redox potential is too low.
Usually the surface of the platinum electrode is gradually covered up by a layer of
contaminants which may not be visible. The ceramic membrane may also be
contaminated or scaled by calceous deposits.
Remove the Redox probe from the flow-through assembly and clean the platin-
um electrode with water and some fine abrasive household cleaning powder.
Take
a bit of cleaning powder and rub the platinum electrode between your finger tips until
it becomes shiny. Rinse thorougly with water and replace the probe without touching
the platinum electrode.
After a running-in period of 3 to 4 hours, the probe will again be ready for
operation.
To remove calceous deposits , immerse the probe for a few minutes in hydrochloric
acid (strength 10 %) just beyond the membrane. Rinse thoroughly with water.
Remove oil and grease with denaturated alcohol or acetone . Rinse probe thoroughly
with water.
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