YOKOGAWA EXAxt ZR22G, User Manual, Page: 186 / 211

<12. Troubleshooting>
12-5
IM 11M12A01-02E 16th Edition : Mar. 19, 2020-00
Table 12.2 Types of Alarms and Reasons for Occurrence
Alarm
Code
Alarm Type Occurrence Conditions
Alarm 1 Oxygen concentration
alarm
Measured oxygen concentration value exceeds or falls below the preset
alarm limits. (refer to Section 8.3, Setting Alarms).
Alarm 2 Humidity alarm Occurs when the humidity to be measured exceeds or falls below the set
alarm points (refer to Section 8.3, “Alarm Setting”).
Alarm 3 Mixing-ratio alarm Occurs when the mixing ratio to be measured exceeds or falls below the
set alarm points (refer to Section 8.3, “Alarm Setting”).
Alarm 6 Zero-point calibration
coefficient alarm
In automatic or semi-automatic calibration, zero correction ratio is outside
the range of 100 ±30%. (refer to Section 9.1.4, Compensation).
Alarm 7 Span-point calibration
coefficient alarm
Span correction ratio is outside the range of 0±18% (refer to Section 9.1.4,
Compensation).
Alarm 8 EMF stabilization
time-up alarm
In automatic or semi-automatic calibration, cell voltage does not stabilize
after calibration time is up.
Alarm 9 Exhaust gas
temperature alarm
When “mA-input” is selected in the Exhaust gas setup display, this alarm
occurs if the exhaust gas temperature exceeds the set alarm values (refer
to Section 8.6.4, “Setting Measurement Gas Temperature and Pressure”).
Alarm 10 Cold junction
temperature alarm
Temperature of the cold junction placed in the detector terminal box falls
below -25ºC or exceeds 155ºC.
Alarm 11 Thermocouple
voltage alarm
Generated when thermocouple voltage exceeds 42.1 mV (about 1020 ºC)
or falls below -5 mV (about -170ºC).
Alarm 12 Input current alarm When “mA-input” is selected in the Exhaust gas setup display, this alarm
occurs if the input current from the temperature transmitter is outside from
3.2 to 21.6 mA.
Alarm 13 Battery low alarm Internal battery needs replacement.
If an alarm is generated, actions such as turning off the heater power are not carried out. The
alarm is cancelled when the cause of the alarm is removed. However, Alarm 10 and/or Alarm 11
may be generated concurrently with Error2 (heater temperature error). In this case, the operation
when the error occurs has priority.
If the power to the converter is turned off after an alarm is generated and the converter is restarted
before the cause of the alarm has been removed, the alarm will be generated again. However,
Alarms 6, 7, and 8 (alarms related to calibration) are not generated unless calibration is executed.
12.2.2 Remedies When Alarms are Generated
n
Alarm 1, Alarm 2, and Alarm 3: Oxygen Concentration Alarm, Humidity
Alarm and Mixing Ratio Alarm
This alarm is generated when a measured value exceeds an alarm set point or falls below it. For
details on these alarms, see Section 8.3, Setting Alarms, in the chapter on operation.
n
Alarm 6: Zero-point Calibration Coefficient Alarm
In automatic or semi-automatic calibration, this alarm is generated when the zero correction ratio
is out of the range of 100 ± 30% (refer to Section 9.1.4, Compensation).
The following are possible causes of this alarm.
(1) The zero-gas oxygen concentration does not agree with the value of the zero-gas
concentration set in Calibration setup. Otherwise, the span gas is used as the zero gas.
(2) The flow rate of zero gas is out of the specified flow (600 ± 60 ml/min).
(3) The sensor assembly is damaged and so cell voltage is not normal.