Yokogawa Multi Channel Oxygen Analyzer System ZR22/AV550G - Manual (Page 205)

IM 11M12D01-01E 11-11
11. Inspection and Maintenance
11.3.8 Stopping and Re-starting Operation
<Stopping Operation>
When operation is stopped, take care of the following so that the sensor of the detector
cannot become unused.
CAUTION
When operating an instrument such as boiler or industrial furnace is stopped with the
zirconia oxygen analyzer operation, moisture can condensate on the sensor portion and
dusts may stick to it.
If operation is restarted in this condition, the sensor which is heated up to 750
؇ C may
become permanently contaminated. The dust can greatly degrade sensor performance. If
a large amount of water is condensed, the sensor can be broken and never re-useful.
To prevent the above nonconformity, take the following action when stopping operation.
(1) If possible, keep on supplying the power to converter and flowing reference air to
the sensor.
If impossible to do the above, remove the detector.
(2) If impossible to supply the power or remove the detector, at least keep on flowing
air at 600ml/min into the calibration gas pipe.
<Restarting Operation>
When restarting operation, be sure to flow air, for 5-10 minutes, at 600ml/min into the
calibration gas pipe before supplying the power to converter
This is not necessary if the purging is specified and the detector is configured so that the
calibration gas is introduced before warm-up.