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Instruction Manual
OCX 8800
Cal Warning (Calibration warning) Cal Failed (Calibration failed)
Probable Cause
Recommended Corrective Action
Calibration gas supply low or gas connection leaking
Check calibration gas supplies and connections. Adjust gas pressure and flow. Replenish low calibration gas supplies and tighten or repair loose or leaking connections. When calibration gas supplies are adequate, recalibrate.
O2 cell degraded or failed | Check O2 cell impedance by reading the O2 Cell Imped value via the LOI (see | |
| Figure | |
| impedance is zero, replace O2 cell. If cell impedance is less than 5000 ohms, check for | |
| cell housing ground fault. Repair ground fault. If cell impedance is greater than 5000 | |
| ohms and no ground fault is indicated, replace O2 cell. | |
| Flow calibration gas to the O2 cell. Read the cell millivolt output. Plot the cell millivolt | |
| output and the calibration gas O2 concentration on the chart shown in Figure | |
| plotted values do not fall on the slope line shown in Figure | |
COe sensor degraded | Replace COe sensor or increase warning level (SYSTEM, CALIB SETUP, COe Slope | |
| Warn via HART.) | |
Low sample gas flow in sensor housing due to | Check the following portions of the flow path for plugging: | |
flow path plugging | • | blowback filter |
| • | |
| • | eductor outlet path |
|
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Table continued on next page
Figure 8-2. Oxygen and Cell
Output
OXYGEN CONCENTRATION (%)
20
(23)
10
9
8
7
6
5
4
3
2
(73)
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0 | 20 | 40 | 60 | 80 | 100 | 120 |
ANALYZER OUTPUT (MILLIVOLT)
37390051