YOKOGAWA ZO21DW, User Manual, Page: 35 / 39

<7. INSPECTION AND MAINTENANCE>
7-6
IM 11M03A02-00E
7.1.3 Stopping and Re-starting Operation
<Stopping Operation>
When operation is stopped, take care of the followings 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 firmly fix the
dusts on itself. Consequently, the dusts can make the sensor performance very lower. 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 unavoidably impossible to supply the power and removing the detector, keep on following
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.