Yokogawa Single Channel Oxygen Analyzer System ZR22/ZR402 - Manual (Page 19)

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IM 11M12A01-01E-A
Maintenance and Trouble Shooting
8.1 Maintenance
The High Temperature Adapter is structured so that the gas to be measured is directed 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, as the gas flow is significantly reduced. If a high
temperature adapter/detector combination is used, it must be inspected periodically and cleaned if
any part of the assembly becomes clogged with dust or particulates.
Dust found sticking to the probe itself should be blown off using low pressure compressed air, or
use a soft cloth with distilled water. For maintenance, inspection and cleaning of the ZR22G Oxygen
Detector please refer to instruction manual IM 11M12A01-02E, Chapter 11.
Should any dust or particulate remains after the initial cleaning, attempt to remove the contaminant
with a metal rod or metallic brush. A removable port (blank-off plate) is located at the top of the
high temperature adapter for cleaning the internal portion of the high temperature adapter and the
transport tube area.
If dust or heavy particulate is found in the eductor assembly, remove the eductor and blow out the
contaminant with low pressure compressed air or rinse with distilled water.
CAUTION: DO NOT use water to clean any parts of the High Temperature Adapter or ZR22G
Oxygen Detector that are used in Lime Kiln operations.
8.2 Troubleshooting
Problem 1: Block valve remains closed after blowback cycle is ended, and a pressure build up
has occurred.
Possible cause(s): The pressure switch attached to the blowback inlet has given a contact to the
system to keep the valve closed in order to protect the probe from damage.
To remove a pressure build up:
1. Turn off air supply to the eductor
2. Slowly loosen the fitting at the blowback inlet connection to allow the pressure to bleed off.
CAUTION: Process gases may be extremely hot. Use caution when loosening the fitting on the
blowback connection.
3. Remove power from the ZR402G or AV550G blowback circuitry.
4. Tighten the fitting at the blowback inlet, so that a leak does not occur. A leak will cause a high
reading during normal operations.
5. Remove the blind flange and gasket, and manually clean out the transport tube as listed in section
8.1above.
6. Once the clog has been removed, replace the gasket and blind flange.
7. Return system to normal operation