Yokogawa GD40 Gas Density Detector - Manual (Page 172)

<11. INSPECTION AND MAINTENANCE>
11-3
IM 11T3E1-01E
11.2 Inspection In Case of Failure
11.2.1 Inspecting the Analyzer in an Alarm Status
The GD402 analyzer outputs an ALARM signal through terminals 16 and 17 if a failure is de-
tected by the self-diagnostic function during measurement. In addition, the <ALARM> lamp on
the operation panel comes on and the message field shows an alarm number. The analyzer out-
puts no contact signal, however, if the alarm number is [ALM.09]. If a failure (alarm) is detected,
take the corrective action given in Table 11.1.
Table 11.1 Corrective Actions when an Alarm Status Is Detected
Message
Shown
Failure Type Diagnostic Conditions Corrective Actions
Message via
Communication
ALM.01 High/low limit alarm
against physical
density
Physical density ≤ Low-limit-of-
physica-density alarm setpoint
Physical density ≥ High-limit-of-
physical-density
Change the high/low
limits.
OUT OF DENSITY
ALM.02 High/low limit alarm
against compensated
density
Compensated density ≤ Low-limit-of-
compensated-density alarm setpoint
Compensated density ≥ Hgh-limit-of-
compensated-density alarm setpoint
Change the high/low
limits.
OUT OF COMP
DENSITY
ALM.03 High/low limit alarm
against specific gravity
Specific gravity ≤ Low-limit-of-specific
gravity alarm setpoint
Specific gravity ≥ High-limit-of-specific
gravity alarm setpoint
Change the high/low
limits.
OUT OF SP GR
ALM.04 High/low limit alarm
against calorific value
Calorific value ≤ Low-limit-of-calorific-
value alarm setpoint
Calorific value ≥ High-limit-of-calorific-
value alarm setpoint
Change the high/low
limits.
OUT OF CALORY
ALM.05 High/low limit alarm
against molecular
weight
Molecular weight ≤ Low-limit-of-
molecular weight alarm setpoint
Molecular weight ≥ High-limit-of-
molecular weight alarm setpoint
Change the high/low
limits.
OUT OF
MOLECULE
ALM.06 High/low limit alarm
against concentration
Concentration ≤ Low-limit-of-
concentration alarm setpoint
Concentration ≥ High-limit-of-
concentration alarm setpoint
Change the high/low
limits.
OUT OF CONC
ALM.07 Error in pressure input
range
Zero point -3% ≥ pressure
Span point +5% ≤ pressure
Pressure ≤ 0.1 kPa
Check the sample-gas
pressure and the
pressure range.
OUT OF GAS
PRESS
ALM.08 Abnormal sample gas
temperature
-25 °C ≤ sample gas temperature
≤ 80 °C
Use the sample gas
within the tolerance
limits.
OUT OF GAS
TEMP
ALM.09 Battery failure Contact Yokogawa
service personnel.
LOW BATTERY
ALM.10 Error in calibration
(zero and span points)
-0.3000 ≤ zero calibration value
≤ 0.3000
0.50000 ≤ span calibration value
≤ 1.5000
Redo calibration. ILLEGAL CALIB