YOKOGAWA ZR22S, User Manual

Page: 173 / 206

<11. Inspection and Maintenance>
11-9
11.1.6 Cleaning the High Temperature Probe Adapter
CAUTION
• Do NOT subject the probe of the High Temperature Probe Adapter (ZO21P) 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
assembly 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 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.
IM 11M13A01-02E