Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 176)

<3. Basic Operation and Startup>
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IM 11B08A01-01E
(9) The indication remains OFF until FID becomes Combustion. When ignition failed, the
alarms of DET1-1 FRAME OUT, DET1-2 FRAME OUT, DET2-1 FRAME OUT, DET2-2
FRAME OUT, DET3-1 FRAME OUT, and DET3-2 FRAME OUT are raised. In this case,
restart the procedure from the beginning.
(10) When FID becomes Combustion, the indication changes from OFF → ON.
(3) FPD
Turn on (ignite) FPD after the temperature of the isothermal oven has become substantially
stable. It takes 2 to 4 hours for the temperature to become stable (the maximum temperature of
the isothermal oven is 145°C). After the temperature of the isothermal oven has become stable,
the Thermocouple signal on the Detector signal screen (see Figure 1.12) becomes 0 mV. After
the power is supplied, the temperature of the isothermal oven rises, and the Thermocouple signal
changes from 0 mV → –3 to –2 mV → 0 mV until the temperature becomes stable. When FPD is
turned on (ignition) at the Thermocouple signal of –3 to –2 mV, the Thermocouple signal does not
exceed the Flame detection signal level and remains at the Combustion stop though combustion
occurs, and the alarms of DET1-1 FRAME OUT, DET2-1 FRAME OUT, and DET3-1 FRAME
OUT are risen.
FPD is ignited with a platinum coil. Only the supply of carrier gas, combustion hydrogen, and
combustion air may cause self-ignition by catalysis of the platinum coil. Self-ignition can be
detected by water drops attached to the vent line. When FPD is turned on under self-ignition,
peaks may not appear on the chromatogram and only the baseline may be output. When self-
ignition occurred, turn on FPD after changing the Flame detection level in the Detector signal
setting. The procedure to turn on FPD is as follows:
(1) Confi rm that the temperature of the isothermal oven has become stable.
(2) Set the pressure of combustion air to twice as large as the value described in the Operating
condition setting in the Operation data.
(3) Press the (OPR) in the navigation bar on the analyzer operation screen.
(4) Check the temperatures on the Oven information display section in the User level SYS tab.
(5) Set the operation mode to Manual in the GCM tab.
(6) Press GCM Det Control in the GCM tab.
(7) Confi rm that the Thermocouple signal on the Detector signal screen (see Figure 1.12) is
0±0.1 mV.
(8) Press ON/OFF under FPD.
(9) The message “Turn on” appears on the screen, and then press Yes.
CAUTION
When self-ignition occurred (the Thermocouple signal becomes higher than 2 to 3 mV), set the
Flame detection level to the value of the Thermocouple signal +0.5 mV.
(10) The indication remains OFF until FPD becomes Combustion. When ignition failed, the
alarms of DET1-1 FRAME OUT, DET2-1 FRAME OUT, and DET3-1 FRAME OUT are
raised. In this case, restart the procedure from the beginning.
(11) When FPD becomes Combustion, the indication changes from OFF → ON.
(12) Return the Flame detection level to the value described in the Operating condition setting in
the Operation data.
(13) After one minute has elapsed after FPD became Combustion, return the pressure of
combustion air to the value described in the Operating condition setting in the Operation
data.
2nd Edition : May 11, 2012-00
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