Yokogawa Single Channel Oxygen Analyzer System ZR22/ZR402 - Manual (Page 180)

IM 11M13A01-02E 11-9
11. Inspection and Maintenance
11.1.6 Cleaning the High-temperature Probe Adapter
CAUTION
• Do NOT subject the probe of the High-temperature Probe Adapter (ZO21P-H-A) to
shock. This probe uses silicon carbide (SiC) which may become damaged if it is
subjected to a strong shock or thermal shock.
The high-temperature detector is structured so that the gas to be measured is directed
toward the detector with the high-temperature probe adapter. Therefore, if the probe or
the sample gas outlet clogs, a precise measurement is no longer possible because of no
gas flow. If you use the high-temperature detector, you have to inspect it periodically
and, if any part of it is significantly clogged with dust, clean it.
Dust found sticking to the probe should be blown off. If any dust still remains after the
blowing, clean it with a metal rod, etc., inserted. In addition, if dust is found on the
auxiliary ejector or needle valve (choke) at the sample gas outlet, remove these parts
from the high-temperature probe adapter and then clean them. To remove dust, blow air
on them or rinse them with water.
11.1.7 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.