Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 136)

<11. Inspection and Maintenance>
11-7
IM 11M12A01-04E
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 fixes 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 be used.
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 gas 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
600 ml/min into the calibration gas pipe.
<Restarting Operation>
When restarting operation, be sure to flow air, for 5-10 minutes, at 600 ml/min into the calibration gas
pipe before supplying the power to converter.