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

IM 11M12A01-03E 11-8
11.1.4 Replacement of O-ring
The detector uses three different types of O-rings (14), (21), and (22). One O-ring alone
(14), or two O-rings (21) and (22) are used. (For a pressure-compensating model, two O-
rings are used for individual uses. Two O-rings (21) and (22) are used for reference-gas
sealing and require periodic replacement.
11.1.5 Stopping and Re-starting Operation
When operation is stopped, take care of the followings so that the sensor of the detector
cannot become unused.
T11.1.5E.ES
Part No. Description
(7) K9470BJ Metal ring
(14) K9470ZS Metal ring with grease
(21) Two pairs of O-rings
(22) with grease
K9470ZP
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
ЊC 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.
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.