Instruction manual

SM425 INSTRUCTION MANUAL 12.0 TROUBLESHOOTING
Figure 12-5 Detailed Data Display
Figure 12-6 Calibration History
5. If deterioration of the sensor assembly has occurred abruptly, it may indicate the check valve
which prevents moisture in the process gas from getting into the calibration gas tubing, has fa
If process gas ge
,
iled.
ts into the calibration gas tubing, it condenses and remains in the gas tubing.
d
ckly.
mbly status in the
following procedure:
a. Select “Cell resistance” by pressing the ▼ key. A new cell will show a cell resistance
value of 2 of its service life will
show a re
b. Display “Cell robustne A good cell (sensor) will show “Life >
1 year” (Figure 12-7).
The condensate is blown into the sensor assembly by the calibration gas during calibration an
causes the cell to cool qui
6. If the sensor assembly has been gradually deteriorating, check the sensor asse
00Ω or less. A cell (sensor) that is approaching the end
sistance value of 3 to 10 kΩ.
ss” by pressing the ▼ key.
Figure 12-7 Cell robustness display
12.2.2.3 Alarm 7: Span-point Calibration Coefficient Alarm
In automatic or semiautomatic calibration, this alarm is generated when the span correction factor is out
of the range of 0 ± 18% (refer to Section 1.51.3, “Calibraton Curves”). An Alarm 7 may be caused by any
of the following:
1. The oxygen concentration of the gas does not agree with the value set for the span gas in
“Calibration setup” menu.
2. The flow of the span gas is out of the specified flow (600 ± 60 mL/min) range.
3. The sensor assembly is damaged.
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