Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 161)

IM 11M13A01-04E 12-7
12. Troubleshooting
12.2.2.4 Alarm 8: EMF Stabilization Time Over
This alarm is generated if the sensor (cell) voltage has not stabilized even after the
calibration time is up for the reason that the calibration gas (zero gas or span gas) has
not filled the sensor assembly of the detector.
<Cause of alarm>
(1) The flow of the calibration gas is less than normal (a specified flow of 600
Ϯ 60 ml/
min).
(2) The length or thickness of the calibration gas tubing has been changed (lengthened
or thickened).
(3) The measuring gas flows toward the tip of the probe.
(4) The sensor (cell) response has deteriorated.
<Search for cause of failure and taking measure>
(1) Carry out calibration by passing the calibration gas at the specified flow (600
Ϯ 60
ml/min) after checking that there is no leakage in the tubing.
(2) If calibration is carried out normally, perform a steady operation without changing
the conditions.
If the error occurs again, check whether or not the reason is applicable to the
following and then replace the sensor assembly.
• A lot of dust and the like may be sticking to the tip of the sensor. If dust is found,
clean and remove the dust (see Section 11.1.1).
In addition, if an error occurs in calibration even after the sensor assembly is replaced,
the influence of measured gas flow may be suspected. Do not let the measured gas flow
toward the tip of the detector probe, for example, by changing the mounting position of
the detector.
12.2.2.5 Alarm 10: Cold Junction Temperature Alarm
The equipment incorporates a temperature sensor. An alarm is issued when the sensor
temperature exceeds 85˚C. If internal temperature of this equipment exceeds 85˚C, the
electronics may fail.
<Search for cause of failure and taking measure>
This equipment can be used at ambient temperatures up to 55˚C. If the ambient tempera-
tures may exceed the limits, take appropriate measures — such as applying heat insulat-
ing material to the furnace walls, and adding a sun shield to keep out direct sunlight.
If this alarm occurs even when the ambient temperature is under 55˚C, the electronics
may be defective. Contact your local Yokogawa service or sales representative.