MODEL SOLU COMP II
SECTION 8.0
TROUBLESHOOTING
8.3 TROUBLESHOOTING WHEN NO ERROR MESSAGE IS SHOWING — OZONE
8.3.1 Zero current is too high
A. Is the sensor properly wired to the analyzer? See Section 3.3.
B. Is the zero solution ozone-free? Take a sample of the solution and test it for ozone. The concentration should
be less than 0.01 ppm.
C. Has adequate time been allowed for the sensor to reach a minimum stable residual current? It may take sev-
eral hours, sometimes as long as overnight, for a new sensor to stabilize.
D. Check the membrane for damage and replace it if necessary.
8.3.2 Zero current is unstable
A. Is the sensor properly wired to the analyzer? See Section 3.3. Verify that all wiring connections are tight.
B. Readings are often erratic when a new or rebuilt sensor is first placed in service. Readings usually stabilize
after about an hour.
C. Is the space between the membrane and cathode filled with electrolyte solution and is the flow path between
the electrolyte reservoir and membrane clear? Often the flow of electrolyte and be started by simply holding
the sensor with the membrane end pointing down and sharply shaking the sensor a few times as though shak-
ing down a clinical thermometer.
If shaking does not work, try clearing the holes around the cathode stem. Hold the sensor with the membrane
end pointing up. Unscrew the membrane retainer and remove the membrane assembly. Use the end of a
straightened paper clip to clear the holes at the base of the cathode stem. Replace the membrane.
Verify that the sensor is filled with electrolyte solution. Refer to the sensor instruction manual for details.
Problem
See Section
Zero current was accepted, but the current is outside the range -10 to 10 nA
8.3.1
Error or warning message appears while zeroing the sensor (zero current is too high)
8.3.1
Zero current is unstable
8.3.2
Sensor can be calibrated, but the current is less than about 250 nA/ppm at 25°C
8.3.3
Process readings are erratic
8.3.4
Readings drift
8.3.5
Sensor does not respond to changes in ozone level
8.3.6
Ozone readings are too low
8.3.7
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