Shimadzu GC-2010 Plus User Manual

3 AFC, APC
3.4 AFC and APC control
39
GC-2010 Plus
3.4.4 Split mode: “DIRECT”
The AFC offers three types of DIRECT mode, FLOW, PRESS and VELOCTY.
When the Control mode is set to “FLOW”, the TFC controls the total flow rate as shown in
Fig. 3.4.3. At that time, the column inlet pressure varies depending on the column type, the
purge flow rate and the column oven temperature.
When the Control mode is set to “PRESS”, the AFC controls the TFC (Total Flow Controller)
to keep the column inlet pressure constant. The control method is equivalent to the sampling
time in SPLITLESS mode. The control diagram is shown in Fig.3.4.2
When the Control mode is set to “VELOCITY”, the column inlet pressure is set to a value
which keeps the linear velocity constant despite changes in the column oven temperature.
Even if the column oven temperature changes, as in programmed temperature analysis, the
linear velocity is always kept constant. Generally, when the column oven temperature
increases, the viscosity of the carrier gas also increases, and does not flow as easily.
Fig. 3.4.3 Direct Control
Flow rate
sensor
CARRIER IN
(GC rear)
PURGE VENT
Column oven
(50 )
TFC
(Total Flow Controller)
Pressure sensor
Pressure sensor
Control mode “FLOW”
Control mode “PRESS” or “VEROCITY”
SPC
(Septum Purge Controller)
Detector
7 ml/min
7 ml/min
CCC
PP
3 ml/min
3 ml/min
4 ml/min

Shimadzu GC-2010 Plus Specifications

General

Type	Gas Chromatograph
Model	GC-2010 Plus
Manufacturer	Shimadzu
Maximum Temperature Ramp Rate	120 °C/min
Detector Options	FID, TCD, ECD, FPD, NPD, MS
Electronic Flow Control (EFC)	Yes
Data Sampling Rate	Up to 250 Hz
Column Oven Temperature Range	Ambient +5°C to 450°C
Maximum Oven Heating Rate	120 °C/min
Injection Port	Split/Splitless, PTV
Display	LCD