Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 159)

<3. Basic Operation and Startup>
3-8
IM 11B08A01-01E
(3) When is pressed, the set pressure, present pressure, and EPC ON/OFF status of the
Carrier n-n-1 to n-4 and Utility n-1 to n-4 are indicated.
Figure 3.9
NOTE
Measure the pressure and fl ow rate of each gas after the temperatures of the isothermal oven
have fully stabilized. If the temperature is low, the pressure is likely to be higher. The time
required for the temperature to stabilize depends on the set temperature: the isothermal oven
with the temperature of below 146°C requires 2 to 4 hours, and the one with the temperature
of at or above 146°C requires 4 to 8 hours. For the FID or FPD detector, the “Therm signal”
on the Detector Status screen becomes 0 mV after the temperature of the isothermal oven
has stabilized (see Figure 3.8). See Section 3.1.4, “How to Check the Operating Status of the
Detector”.
For the FID and FPD, a carrier gas, combustion gas, and combustion air are discharged together
from the DET vent. Therefore, before measurement close the primary valves of cylinders of
gases that are not to be measured. For the FID and FPD, supplying the gas may simply result
in natural ignition. In the Flame on status, condensation forms on the vent line and the “Therm
signal” on the Detector Status screen indicates 2 to 6 mV. Measure the gas fl ow rate under the
condition that the “Therm signal” is 0 mV.
2nd Edition : May 11, 2012-00