Yokogawa Integral Oxygen Analyzer ZR202 - Manual (Page 167)

IM 11M12A01-05E 12-4
12.2 Displays and Measures to Take When Alarms are Gen-
erated
12.2.1 What is an Alarm?
When an alarm occurs, the alarm indication blinks in the display to notify of the alarm
(Figure 12.4). Pressing the alarm indication displays a description of the alarm. Alarms
include those shown in Table 12.2.
Displayed alternately
AL-06 0.0%
↔
F12.4E.EPS
Figure 12.4
Table 12.2 Types of Alarms and Reasons
T12.2E.EPS
Alarm Type of alarm Reason for occurrence
Oxygen concentration alarm
Alarm 1 concentration alarm Occurs when a measured value exceed or falls below
through 3 humidity, and mixing ratio alarms the set alarm value (refer to Section 8.3, "Alarm Setting").
Alarm 6 Zero-point calibration coefficient alarm Generated when the zero correction factor is
out of the range of 100 6 30% in automatic and
semiautomatic calibration (refer to Section 9.1.3,
"Compensation").
Alarm 7 Span-point calibration coefficient alarm Generated when the span correction factor is out
of the range of 0 6 18% in automatic and semiautomatic
calibration (refer to Section 9.1.3, "Compensation").
Alarm 8 EMF stabilization time-up Generated when the cell (sensor) voltage is not
stabilized even after the calibration time is up in
automatic and semiautomatic calibration.
Alarm 10 Cold junction temperature alarm Occurs when an equipment internal temperature
exceeds 858C.
Alarm 11 Thermocouple voltage alarm Generated when thermocouple voltage exceeds 42.1 mV
(about 10208C ) or falls below -5 mV (about -1708C).
Alarm 13 Battery low alarm Internal battery needs replacement.
If an alarm occurs, such measures as turning off the heater power are not carried out.
The alarm is released when the cause for the alarm is eliminated. If the analyzer power
is turned off after an alarm occurs, and then turned on before the cause of the alarm is
eliminated, the alarm will occur again. However, alarms 6, 7, and 8 (alarms related to
calibration) are not generated unless calibration is executed.
12.2.2 Measures Taken When Alarms Occur
12.2.2.1 Alarms 1 through 3: Oxygen Concentration, Humidity, and Mixing Ratio Alarms
These alarms occur when a measured value exceeds an alarm setpoint or falls below it.
For more details, see Section 8.3, “Alarm Setting,” earlier in this manual.
12.2.2.2 Alarm 6: Zero-point Calibration Coefficient Alarm
In calibration, this alarm is generated when the zero correction factor is out of the
range of 100 630% (refer to Section 9.1.3, “Compensation”). The following can be
considered the causes for this:
(1) The zero-gas oxygen concentration does not agree with the value of the zero-gas
concentration set (refer to Section 9.2.1,“Calibration Setup”). Otherwise, the span
gas is used as the zero gas.
(2) The zero-gas flow is out of the specified flow (600 6 60 mL/min).
(3) The sensor assembly is damaged and so cell voltage is not normal.