
3 of 30
Jun 2001
Agilent 6890 Gas Chromatograph Service Manual
Volatiles Interface
250
Theory of operation
During sampling
, pressure upsets caused by switching valves in the external
sampling device can cause fluctuations in column flow rates. To compensate
for this, the interface is flow controlled during sampling time. The sampling
flow rate is calculated from the pressure setpoint that is active when sample
introduction begins. This flow control starts when the GC goes into the Pre
Run state (when your system is automated and the Pre Run light is on or
during manual operation when you press [Prep Run]) and ends after the
interface’s
Sampling end
setpoint expires.
During this user-specified sampling period, the solenoid valve is closed. Flow
to the interface is measured by a flow sensor and controlled by a proportional
valve. See Figure 250-2.
After sampling end
, the solenoid valve opens. Flow to the interface is again
measured by a flow sensor and controlled by a proportional valve while
column flow is controlled via back-pressure regulation. The purge flow is
controlled by the user. If desired, gas saver can be turned on at the end of the
run. See Figure 250-1.
Содержание 6890 Series
Страница 1: ...6890 Series Gas Chromatograph Service Manual ...
Страница 2: ...6890 Series Gas Chromatograph Service Manual ...
Страница 27: ...24 of 24 Jun 2001 Contents Contents Agilent 6890 Gas Chromatograph Service Manual ...
Страница 29: ......
Страница 39: ......
Страница 195: ...260 Solvent Vapor Exit Accessory Leak testing 10 of 10 Jun 2001 Inlets Agilent 6890 Gas Chromatograph Service Manual ...
Страница 207: ......
Страница 389: ...360 Auxiliary EPC Replacement procedures 16 of 16 Jun 2001 Detectors Agilent 6890 Gas Chromatograph Service Manual ...
Страница 391: ......
Страница 459: ......
Страница 479: ...520 Gases Supplying valve actuator air 14 of 14 Jun 2001 Site Preparation Agilent 6890 Gas Chromatograph Service Manual ...
Страница 485: ...530 Power Grounding 6 of 6 Jun 2001 Site Preparation Agilent 6890 Gas Chromatograph Service Manual ...
Страница 491: ...540 Instrument Specifications Detectors 6 of 6 Jun 2001 Site Preparation Agilent 6890 Gas Chromatograph Service Manual ...
Страница 492: ...600 Performance Verification How to check the performance of the 6890 instrument 610 Checkout Chromatograms ...
Страница 493: ......
Страница 521: ......
Страница 523: ......
Страница 555: ...840 Shutdowns 10 of 10 Jun 2001 Error Codes and Internal Diagnostics Agilent 6890 Gas Chromatograph Service Manual ...
Страница 580: ...900 Remote Access Remote Access information was not available for this printing ...
Страница 581: ......
Страница 583: ......
Страница 631: ......
Страница 637: ...1110 Valves Liquid sample valves 6 of 6 Jun 2001 Valves Agilent 6890 Gas Chromatograph Service Manual ...
Страница 647: ...1120 Valve Box Removing the valve box assembly 10 of 10 Jun 2001 Valves Agilent 6890 Gas Chromatograph Service Manual ...
Страница 675: ...1150 Troubleshooting Pressure check 6 of 6 Jun 2001 Valves Agilent 6890 Gas Chromatograph Service Manual ...
Страница 677: ......
Страница 717: ...1225 Main Board 6890N Fuses 6 of 6 Jun 2001 Electrical Agilent 6890 Gas Chromatograph Service Manual ...
Страница 737: ......