Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 175)

<3. Basic Operation and Startup>
3-24
IM 11B08A01-01E
(1) TCD
When TCD is turned on with air fi lled in the carrier gas line, the fi lament of TCD may burn out.
Continue to let carrier gas fl ow for at least 10 minutes before turning on TCD. The output of TCD
does not become stable until the temperature becomes stable (the baseline drifts). Do normal
operation and calibration after at least 12 hours have elapsed after TCD was turned on.
Procedure
(1) Confi rm that the temperature of the isothermal oven has become stable.
(2) Check the temperatures on the Oven information display section in the User level SYS tab.
(3) Press
the (OPR) in the navigation bar on the analyzer operation screen.
(4) Set the operation mode to Manual in the GCM tab.
(5) Press GCM Det Control in the GCM tab.
(6) Press ON/OFF under TCD.
(7) The message “Turn on” appears on the screen, and then press Yes.
(2) FID and FID with a methanizer
Turn on (ignite) FID after the temperature of the isothermal oven has become substantially
stable. Depending on the set temperature, it takes 2 to 4 hours for the temperature to become
stable when the temperature of the isothermal oven is 145°C or less and 4 to 8 hours when the
temperature of the isothermal oven is higher than 146°C. After the temperature of the isothermal
oven has become stable, the Thermocouple signal on the Detector signal screen becomes
0 mV. After the power has been 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 FID 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, DET1-2
FRAME OUT, DET2-1 FRAME OUT, DET2-2 FRAME OUT, DET3-1 FRAME OUT, and DET3-2
FRAME OUT are risen.
FID is ignited with a platinum coil. Only the supply of carrier gas, combustion hydrogen or
makeup gas, 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 FID 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 FID after having set the Flame detection level in the Detector
signal setting to the value of the Thermocouple signal +0.5 mV. The procedure to turn on FID is
as follows:
(1) Confi rm that the temperature of the isothermal oven has become stable.
(2) Press
the (OPR) in the navigation bar on the analyzer operation screen.
(3) Check the temperatures on the Oven information display section in the User level SYS tab.
(4) Set the operation mode to Manual in the GCM tab.
(5) Press GCM Det Control in the GCM tab.
(6) Confi rm that the Thermocouple signal of FID is 0 ± 0.1 mV.
(7) Press ON/OFF under FID.
(8) 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), turn on
FID after having set the Flame detection level to the value of the Thermocouple signal +0.5 mV.
2nd Edition : May 11, 2012-00