YOKOGAWA av550g, User Manual

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< 11. Inspection and Maintenance >
11-11
IM 11M12D01-01E
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 gas 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 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.
This is not necessary if the purging is specified and the detector is configured so that the calibration
gas is introduced before warm-up.