Agilent Technologies 7820A User manual

Agilent Technologies
Agilent 7820A
Gas Chromatograph
Operating Guide

Notices
© Agilent Technologies, Inc. 2011
No part of this manual may be reproduced
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laws.
Manual Part Number
G4350-90012
Edition
Third edition, June 2011
Second edition, October 2009
First edition, March 2009
Printed in China
Agilent Technologies, Inc.
412 Ying Lun Road
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Safety Notices
CAUTION
A CAUTION notice denotes a hazard. It
calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in damage to the product
or loss of important data. Do not
proceed beyond a CAUTION notice
until the indicated conditions are fully
understood and met.
WARNING
A WARNING notice denotes a hazard.
It calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in personal injury or
death. Do not proceed beyond a
WARNING notice until the indicated
conditions are fully understood and
met.

Operating Guide 3
Contents
1 Introduction
Where to Find Information 8
Online User Documentation 8
Agilent Customer Portal 9
Chromatography Using a GC 10
The Front View of the Agilent 7820A GC 11
The Back View of the Agilent 7820A GC 12
The Inlets 13
The GC Column and Oven 15
Detectors 16
The Operating Panel 17
The display 17
Indicator Lights 17
Alert Tones 18
The keypad 19
2 Operating Basics
Overview 22
Instrument Control 23
Correcting Problems 24
To Start Up the GC 25
To Shut Down the GC for Less Than a Week 26
To Shut Down the GC for More Than a Week 27
3 Software Keypad Operation
To Install the Software Keypad 30
The Software Keypad 31
To connect to a GC 31
To disconnect from a GC 32
Other program settings 32
To minimize or expand the software keypad 33
To troubleshoot a connection 33
To get help 34
The Run Keys 35
The Service Mode Key 35

4Operating Guide
The GC Component Keys 36
The Status Key 37
The Info Key 38
The General Data Entry Keys 39
The Supporting Keys 40
Method Storage and Automation Keys 41
Keypad Functionality When the GC Is Controlled by an Agilent Data
System 42
About GC Status in the Software Keypad 43
Indicators 43
Error conditions 43
Blinking setpoint 44
About Logs 45
4 Running a Method or a Sequence from the Software Keypad
Loading, Storing, and Running Methods from the Software Keypad 48
To load a method 48
To store a method 48
To manually inject a sample with a syringe and start a run 48
To run a method to process a single ALS sample 48
To abort a method 49
Loading, Storing, and Running Sequences from the Software Keypad 50
To load a sequence 50
To store a sequence 50
To start running a sequence 50
To pause a running sequence 51
To resume a paused sequence 51
To stop a running sequence 51
To resume a stopped sequence 51
Aborting a sequence 51
To resume an aborted sequence 52
5 About Methods, Sequences, and Data Analysis
What Is a Method? 54
What Is Saved in a Method? 54
What Happens When You Load a Method? 55
What Is a Sequence? 55
Automating Data Analysis, Method Development, and Sequence
Development 55

Operating Guide 5
6 Configuration Tasks
About the GC IP Address 58
To set the IP address at the GC 59
To Use DHCP to Provide the GC IP Address 60
To restore the default GC IP address 61
To Reconfigure the EPC Module for Another Detector 62

6Operating Guide

7
Agilent 7820AGas Chromatograph
Operating Guide
Agilent Technologies
1
Introduction
Where to Find Information 8
Chromatography Using a GC 10
The Front View of the Agilent 7820A GC 11
The Back View of the Agilent 7820A GC 12
The Inlets 13
The GC Column and Oven 15
Detectors 16
The Operating Panel 17
This document provides an overview of the individual
components that make up the Agilent 7820A Gas
Chromatograph (GC).

8Operating Guide
1Introduction
Where to Find Information
In addition to this document, Agilent provides several
learning products that document how to install, operate,
maintain, and troubleshoot the Agilent 7820A GC.
Before operating your GC, be sure to read the safety and
regulatory information included on the Agilent GC and
GC/MS Hardware User Information & Utilities DVD. The
most common safety hazards when working on the GC are:
•Burns caused by touching heated areas on or in the GC
•Release of pressurized gas containing hazardous chemical
compounds caused by opening inlets
•Glass cuts or puncture wounds caused by sharp capillary
column ends
•Use of hydrogen as a GC carrier gas
Online User Documentation
Now your Agilent instrument documentation is in one place,
at your fingertips.
The Agilent GC and GC/MS Hardware User Information &
Utilities DVD that ships with your instrument provides an
extensive collection of online help, videos, and books for
current Agilent gas chromatographs, mass selective detectors,
and GC samplers. Included are localized versions of the
information you need most, such as:
•Getting Familiar documentation
•Safety and Regulatory guide
•Site Preparation information
•Installation information

Introduction 1
Operating Guide 9
•Operating guides
•Maintenance information
•Troubleshooting details
Agilent Customer Portal
Agilent also provides customized information for the
products you own through a customer portal. This web
service provides many customizable services as well as
information related directly to your Agilent products and
orders. Log onto the portal at http://www.agilent.com/chem.

10 Operating Guide
1Introduction
Chromatography Using a GC
Chromatography is the separation of a mixture of
compounds into individual components.
There are three major steps involved with separating and
identifying components of a mixture using a GC. They are:
1Injecting a sample into the GC. (This takes place at the
inlet.)
2Separating the sample into individual components. (This
takes place inside the column in the oven.)
3Detecting what compounds were in the sample. (This is
done in the detector.)
During this process, status messages from the Agilent 7820A
GC are displayed, and user changes to parameter settings
can be made through the software keypad.
Each part of this process is described in brief on the
following pages of this document. Refer to the Advanced
User Guide for more details.
Inlet
Detector
Oven
Operating panel

Introduction 1
Operating Guide 11
The Front View of the Agilent 7820A GC
Detector cover
Detectors
Inlets
Valves (not shown)
Display
Keypad
Power switch
Oven latch

12 Operating Guide
1Introduction
The Back View of the Agilent 7820A GC
Inlet vent
Gas supply connections
Electronic cable
connections
Oven cooling intake and
exhaust vent
Power connection

Introduction 1
Operating Guide 13
The Inlets
Inlets are where samples are injected into the GC. The
Agilent 7820A GC can have a maximum of two inlets,
identified as Front Inlet and Back Inlet.
Two inlets—split/splitless and purged packed—are available.
The type of inlet chosen is based on the type of analysis
being done, the type of sample being analyzed, and the
column being used.
Samples can be injected into the inlets by hand using a
syringe, or an automatic sampling device (such as an Agilent
Automatic Liquid Sampler or Agilent Headspace Sampler).

14 Operating Guide
1Introduction
Automatic injectors
The Agilent 7820A GC can accommodate up to two
autoinjectors, identified as Front Injector and Back Injector.
Automatic gas sampling valves
The sampling valves are simple mechanical devices that
introduce a sample of fixed size into the carrier gas stream.
Valves are most frequently used to sample gases in
constantly flowing streams.
The Agilent 7820A GC can accommodate up to two gas
sampling valves, identified as Valve # 1 and Valve #2.
The valves are located inside the gas sampling valve box.
Autoinjector
Turre t

Introduction 1
Operating Guide 15
The GC Column and Oven
GC columns are located inside a temperature- controlled
oven. Generally, one end of the column is attached to the
inlet, while the other end is attached to the detector.
Columns vary in length, diameter, and internal coating. Each
column is designed for use with different compounds.
The purpose of the column and the oven is to separate the
injected sample into individual compounds as it travels
through the column. To aid this process, the GC oven can be
programmed to speed the sample flow through the column.

16 Operating Guide
1Introduction
Detectors
Detectors identify the presence of compounds as they exit
the column.
As each compound enters the detector, an electrical signal
proportional to the amount of compound detected is
generated. This signal is generally sent to a data analysis
system—such as Agilent ChemStation—where it shows up as a
peak on a chromatogram.
The Agilent 7820A GC can accommodate up to two
detectors, identified as Front Det and Back Det.
A complete selection of detectors (FID, TCD, NPD, FPD,
µECD, and MSD) is available. The type of detector chosen is
based on the type of analysis required.

Introduction 1
Operating Guide 17
The Operating Panel
The operating panel consists of the display, status lights, and
keypad. See “Software Keypad Operation” and the Advanced
User Guide, along with the complete suite of documentation
included on the Agilent GC and GC/MS Hardware User
Information & Utilities DVD that shipped with your
instrument for more detailed information.
The display
The display shows details of what is currently happening in
the Agilent 7820A GC.
Use the scroll keys to view additional lines in the display.
The display shows current temperatures, flows, pressures,
and information about GC readiness.
Indicator Lights
The GC has two status indicators below the display, Run and
Not Ready.
ACTUAL SETPOINT
Stop Prep
Run Start
STATUS READY
Last run 0.15
Next run time 3.00
Oven temperature 35 35
Run Not Ready
Display
Indicator lights
Keys

18 Operating Guide
1Introduction
When the GC is ready to begin a run, the display screen
shows STATUS Ready for Injection. Alternatively, when a
component of the GC is not ready to begin a run, the Not
Ready indicator lights. Scroll to see a message explaining why
the GC is not ready.
Alert Tones
A series of warning beeps sounds before a shutdown occurs.
After a short time the component with the problem shuts
down, the GC emits one beep, and a brief, numbered
message is displayed. For example, a series of beeps sounds
if the front inlet gas flow cannot reach setpoint. The
message Front inlet flow shutdown is briefly displayed. The flow
shuts down after 2 minutes. See “Correcting Problems”.
A continuous tone sounds if a hydrogen flow is shut down
or a thermal shutdown occurs.
One beep sounds when a problem exists, but the problem
will not prevent the GC from executing the run. The GC will
emit one beep and display a message. The GC can start the
run and the warning will disappear when a run starts.
Other messages indicate hardware problems that require
user intervention. Depending on the type of error, the GC
emits no beep or a single beep.
Not Ready Lights when the GC is not yet ready to process a
sample and blinks when a fault occurs. Scroll to see
which parameters are not ready or what faults have
occurred.
Run Lights when the instrument is executing a
chromatographic run. Blinks green when in pre-run
state, for example when a split/splitless inlet is
purging.
WARNING
Before resuming GC operations, investigate and resolve the cause
of the hydrogen shutdown. See Hydrogen Shutdown in the
Troubleshooting manual for details.

Introduction 1
Operating Guide 19
The keypad
The GC has three operating keys.
[Stop] Immediately terminates the run. If the GC is in
the middle of a run, the data from that run
may be lost. Refer to the Advanced User Guide
for information on how to restart the GC after
pressing [Stop].
[Prep Run] Activates processes required to bring the GC to
the starting condition dictated by the method
(such as turning off the inlet purge flow for a
splitless injection or restoring normal flow
from gas saver mode).
[Start] Starts a run after manually injecting a sample.
(When you are using an automatic liquid
sampler or gas sampling valve, the run is
automatically activated at the appropriate
time.)
Scrolls up and down through the display one
line at a time. Use to view:
•Remaining run time
•Next run time
•Current status messages (what the GC is
doing)
•Current temperatures, pressures, and flows
•Valve state
•GC firmware revision
•GC IP address
•System date and time

20 Operating Guide
1Introduction