Emerson 700 XA User Manual
System Reference Manual
2-3-9000-744, Rev G
September 2014
700XA Gas Chromatograph
Applies to the Rosemount® Analytical 700XA Gas Chromatograph
and the Danalyzer™ 700XA Gas Chromatograph
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Warranty
1. LIMITED WARRANTY: Subject to the limitations contained in Section 2 herein and except as otherwise expressly provided
herein, Rosemount Analytical, Inc. (“Seller”) warrants that the firmware will execute the programming instructions provided
by Seller, and that the Goods manufactured or Services provided by Seller will be free from defects in materials or
workmanship under normal use and care until the expiration of the applicable warranty period. Goods are warranted for
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Contents
Contents
Chapter 1 Introduction ...................................................................................................................1
1.1 Description of manual ..................................................................................................................1
1.2 System description ...................................................................................................................... 1
1.2.1 Analyzer assembly .........................................................................................................1
1.2.2 Electronics assembly ..................................................................................................... 1
1.2.3 Sample conditioning system (SCS) ................................................................................ 2
1.3 Functional description ................................................................................................................. 2
1.4 Software description ....................................................................................................................3
1.4.1 Embedded GC firmware ................................................................................................ 3
1.4.2 MON2020 ..................................................................................................................... 4
1.5 Theory of operation ..................................................................................................................... 5
1.5.1 Thermal conductivity detector ......................................................................................5
1.5.2 Flame ionization detector ..............................................................................................7
1.5.3 Liquid sample injection valve .........................................................................................7
1.5.4 Methanator ...................................................................................................................8
1.5.5 Data acquisition ............................................................................................................ 9
1.5.6 Peak detection .............................................................................................................. 9
1.6 Basic analysis computations .......................................................................................................10
1.6.1 Concentration analysis - response factor ..................................................................... 10
1.6.2 Concentration calculation - mole percentage (without normalization) ........................11
1.6.3 Concentration calculation in mole percentage (with normalization) ........................... 12
1.7 Glossary .....................................................................................................................................12
Chapter 2 Equipment description and specifications .................................................................... 15
2.1 Equipment description .............................................................................................................. 15
2.1.1 Front panel assembly .................................................................................................. 15
2.1.2 Upper compartment ................................................................................................... 19
2.1.3 Lower compartment ................................................................................................... 19
2.1.4 Mechanical pressure regulators ...................................................................................20
2.2 Equipment specifications ...........................................................................................................21
2.2.1 Utilities ........................................................................................................................21
2.2.2 Electronic hardware .................................................................................................... 22
2.2.3 Airless analytical oven ................................................................................................. 23
2.2.4 Software ..................................................................................................................... 23
2.2.5 Corrosion protection ...................................................................................................24
2.2.6 Archived Data Storage Capabilities ..............................................................................24
Chapter 3 Installation and setup ...................................................................................................27
3.1 Precautions and warnings .......................................................................................................... 27
3.1.1 Installation considerations .......................................................................................... 29
3.2 XA mounting arrangements ...................................................................................................... 29
3.2.1 Wall mount ................................................................................................................. 30
3.2.2 Pole mount ................................................................................................................. 31
3.2.3 Floor mount ................................................................................................................ 32
3.3 Gas chromatograph wiring ........................................................................................................ 33
3.3.1 Power source wiring ....................................................................................................33
3.3.2 Signal wiring ............................................................................................................... 33
i
Contents
3.3.3 Electrical and signal ground .........................................................................................34
3.3.4 Electrical conduit .........................................................................................................35
3.3.5 Sample system requirements ......................................................................................36
3.4 Preparation ................................................................................................................................37
3.4.1 Site selection ...............................................................................................................37
3.4.2 Unpacking the unit ......................................................................................................37
3.4.3 Required tools and components ..................................................................................38
3.4.4 Supporting tools and components .............................................................................. 39
3.5 Installation .................................................................................................................................39
3.5.1 DC power supply .........................................................................................................39
3.5.2 Optional AC/DC power converter ................................................................................41
3.5.3 Connect the sample and other gas lines ...................................................................... 42
3.5.4 Maximum effective distance by communication protocol type ................................... 45
3.5.5 RS-485 serial port terminals ........................................................................................ 45
3.5.6 Installing and connecting to an analog modem card ................................................... 45
3.5.7 Connecting to the GC via the analog modem .............................................................. 46
3.5.8 Connecting directly to a PC using the GC’s Ethernet port ............................................ 47
3.5.9 Troubleshooting DHCP connectivity issues ................................................................. 50
3.5.10 Connecting directly to a PC using the GC’s serial port ..................................................51
3.5.11 Connecting directly to a PC using the GC’s wired Ethernet terminal ............................ 53
3.5.12 Assigning a static IP address to the GC .........................................................................55
3.5.13 Discrete digital I/O wiring ............................................................................................57
3.5.14 Analog input wiring .....................................................................................................63
3.5.15 Analog output wiring .................................................................................................. 67
3.6 Leak checking and purging for first calibration ...........................................................................72
3.6.1 Checking the GC for leaks ............................................................................................72
3.6.2 Purging carrier gas lines .............................................................................................. 73
3.6.3 Purging calibration gas lines ........................................................................................74
3.7 System startup .......................................................................................................................... 74
Chapter 4 Operation and maintenance .........................................................................................75
4.1 Warning and precautions ...........................................................................................................75
4.2 Start a two-point calibration ...................................................................................................... 75
4.3 Troubleshooting and repair concept .......................................................................................... 76
4.4 Routine maintenance ................................................................................................................ 76
4.4.1 Maintenance checklist .................................................................................................76
4.4.2 Routine maintenance procedures ............................................................................... 78
4.4.3 Precautions for handling PC assemblies .......................................................................78
4.4.4 General troubleshooting ............................................................................................. 78
4.4.5 Checking the GC for leaks ............................................................................................89
4.4.6 Valves ......................................................................................................................... 90
4.4.7 Detector maintenance ................................................................................................ 93
4.4.8 Removing the FID ........................................................................................................95
4.4.9 LSIV maintenance ....................................................................................................... 97
4.4.10 Methanator maintenance ..........................................................................................103
4.4.11 Measure vent flow .....................................................................................................105
4.4.12 Electrical components ...............................................................................................105
4.4.13 Factory settings for jumpers and switches .................................................................110
4.4.14 Communications .......................................................................................................111
4.4.15 Installing or replacing a FOUNDATION fieldbus module ............................................ 119
4.4.16 Analog inputs and outputs ........................................................................................ 126
4.4.17 Discrete digital inputs and outputs ............................................................................126
ii
Contents
4.4.18 Recommended spare parts ....................................................................................... 127
4.4.19 Upgrading the embedded software ...........................................................................127
Appendices and reference
Appendix A Local operator interface ............................................................................................. 129
A.1 Interface components for displaying and entering data ...........................................................129
A.1.1 Light emitting diode indicators ................................................................................. 129
A.1.2 LCD screen ................................................................................................................ 130
A.1.3 Keypad ......................................................................................................................130
A.2 Using the local operator interface ............................................................................................ 131
A.2.1 Start up ..................................................................................................................... 131
A.2.2 Navigating menus ..................................................................................................... 132
A.2.3 Navigating the screen ............................................................................................... 132
A.2.4 Editing numeric fields ................................................................................................134
A.2.5 Editing non-numeric fields ........................................................................................ 135
A.3 Screen navigation and interaction tutorial ............................................................................... 139
A.4 The LOI screens ........................................................................................................................145
A.4.1 The Chromatogram menu .........................................................................................147
A.4.2 The Hardware menu ..................................................................................................152
A.4.3 The Application menu ............................................................................................... 157
A.4.4 The Logs/Reports menu ............................................................................................ 162
A.4.5 The Control menu ..................................................................................................... 166
A.4.6 The Manage menu .................................................................................................... 170
A.5 Troubleshooting a blank LOI screen ......................................................................................... 172
Appendix B Carrier gas installation and maintenance .................................................................... 175
B.1 Carrier gas ............................................................................................................................... 175
B.2 Installation and line purging .................................................................................................... 176
B.3 Replacing carrier cylinder .........................................................................................................177
B.4 Calibration gas .........................................................................................................................177
Appendix C Recommended spare parts ......................................................................................... 179
C.1 Recommended spare parts for 700XA TCD analyzers ...............................................................179
C.2 Recommended spare parts for 700XA FID/TCD analyzers ........................................................ 180
C.3 Recommended spare parts for 700XA FID analyzers ................................................................ 181
Appendix D Shipping and long-term storage recommendations ....................................................183
Appendix E Engineering drawings ................................................................................................ 185
E.1 List of engineering drawings .................................................................................................... 185
iii
Contents
iv
Introduction
1 Introduction
This section describes the contents and purpose of the 700XA Gas Chromatograph System
Reference Manual, a description of the Model 700XA system, an explanation of the theory
of operation, and a glossary of chromatograph terminology.
Use this section to get acquainted with the basic engineering of the 700XA.
1.1 Description of manual
The 700XA Gas Chromatograph System Reference Manual (P/N 3-9000-744) consists of
installation, operations, maintenance, and troubleshooting procedures.
1.2 System description
The 700XA is a high-speed gas chromatograph (GC) system that is engineered to meet
specific field application requirements based on typical hydrocarbon stream composition
and anticipated concentration of the selected components. In its standard configuration,
the 700XA gas chromatograph can handle up to eight streams: seven for sample streams
and one calibration stream.
Introduction
1
The 700XA system consists of two major parts: the analyzer assembly and the electronics
assembly. Depending upon the particular GC, there may also be a third, optional, assembly
called the sample conditioning system (SCS).
The 700XA’s electronics and hardware are housed in an explosion-proof enclosure that
meets the approval guidelines of various certification agencies for use in hazardous
environments. See the certification tag on the GC for specific details about agency
approvals.
1.2.1 Analyzer assembly
The analyzer assembly includes the columns, TCDs/FIDs, a preamplifier, a preamplifier
power supply, stream switching valves, analytical valves and solenoids. Additionally, the
700XA can be equipped with a liquid sample injection valve or a methanator.
For more information, see Section 2.1.2.
1.2.2 Electronics assembly
The electronics assembly includes the electronics and ports necessary for signal
processing, instrument control, data storage, personal computer (PC) interface, and
telecommunications. This assembly allows the user to use MON2020 to control the GC.
Refer to Section 2.2.2 for more details.
1
Introduction
The GC-to-PC interface provides the user with the greatest capability, ease-of-use, and
flexibility. MON2020 can be used to edit applications, monitor operations, calibrate
streams, and display analysis chromatograms and reports, which can then be stored as
files on the PC’s hard drive or printed from a printer connected to the PC.
WARNING!
Do not use a PC or a printer in a hazardous area. Serial ports and Modbus communication links
are provided to connect the unit to the PC and to connect to other computers and printers in a
safe area. Failure to follow this warning may result in injury or death to personnel or cause
damage to the equipment.
1.2.3 Sample conditioning system (SCS)
The optional sample conditioning system is located between the process stream and the
sample inlet, which is often mounted below the GC. The standard SCS configuration
includes a stream switching system and filters.
1.3 Functional description
A sample of the gas to be analyzed is taken from the process stream by a sample probe
installed in the process line. The sample passes through a sample line to the SCS where it is
filtered or otherwise conditioned. After conditioning, the sample flows to the Analyzer
Assembly for separation and detection of the gas components.
The chromatographic separation of the sample gas into its components is accomplished in
the following manner. A precise volume of sample gas is injected into one of the analytical
columns. The column contains a stationary phase (packing) that is either an active solid or
an inert solid support that is coated with a liquid phase (absorption partitioning). The
sample gas is moved through the column by means of a mobile phase (carrier gas). The
selective retardation of the components takes place in the column, causing each
component to move through the column at a different rate. This separates the sample into
its constituent gases and vapors.
A detector located at the outlet of the analytical column senses the elution of components
from the column and produces electrical outputs proportional to the concentration of
each component.
Note
For additional information, see Section 1.4.
Output from the electronic assembly is normally displayed on a remotely located PC or a
printer. Connection between the GC and the PC can be accomplished via a direct serial
line, an optional ethernet cable, or via a Modbus-compatible communication interface.
Several chromatograms may be displayed via MON2020, with separate color schemes,
allowing the user to compare present and past data.
2
Introduction
In most cases it is essential to use MON2020 to configure and troubleshoot the GC. The PC
may be remotely connected via ethernet, telephone, radio or satellite communications.
Once installed and configured, the GC can operate independently for long periods of time.
Gas chromatography process modelFigure 1-1:
1.4 Software description
The GC uses three distinct types of software. This enables total flexibility in defining the
calculation sequence, printed report content, format, type and amount of data for
viewing, control and/or transmission to another computer or controller assembly. The
three types are:
• Embedded GC firmware
• Application configuration software
• Maintenance and operations software (MON2020)
Introduction
1
The BOS and the Application configuration software are installed when the 700XA is
shipped. The application configuration is tailored to the customer’s process and shipped
on a CD-ROM. Note that the hardware and software are tested together as a unit before
the equipment leaves the factory. MON2020 communicates with the GC and can be used
to initiate site system setup (i.e., operational parameters, application modifications, and
maintenance).
1.4.1 Embedded GC firmware
The GC’s embedded firmware supervises operation of the 700XA through its internal
microprocessor-based controller; all direct hardware interface is via this control software.
It consists of a multi-tasking program that controls separate tasks in system operation, as
well as hardware self-testing, user application downloading, start-up, and
communications. Once configured, the 700XA can operate as a stand alone unit.
3
Introduction
1.4.2 MON2020
MON2020 is a Windows-based program that allows the user to maintain, operate, and
troubleshoot a gas chromatograph. Individual GC functions that can be initiated or
controlled by MON2020 include, but are not limited to, the following:
• Valve activations
• Timing adjustments
• Stream sequences
• Calibrations
• Baseline runs
• Analyses
• Halt operation
• Stream/detector/heater assignments
• Stream/component table assignments
• Stream/calculation assignments
• Diagnostics
• Alarm and event processing
• Event sequence changes
• Component table adjustments
• Calculation adjustments
• Alarm parameters adjustments
• Analog scale adjustments
• LOI variable assignments (optional)
• Foundation Fieldbus variable assignments (optional)
Reports and logs that can be produced, depending upon the GC application in use,
include, but are not limited to, the following:
• Configuration report
• Parameter list
• Analysis chromatogram
• Chromatogram comparison
• Alarm log (unacknowledged and active alarms)
• Event log
• Various analysis reports
For a complete list of the GC functions, reports, and logs available through MON2020,
consult the software manual (P/N 2-3-9000-745).
MON2020 provides operator control of the 700XA, monitors analysis results, and inspects
and edits various parameters that affect 700XA operation. It also controls display and
printout of the chromatograms and reports, and it stops and starts automatic analysis
cycling or calibration runs.
4
Introduction
After the equipment/software has been installed and the operation stabilized, automatic
operation can be initiated via an ethernet network.
1.5 Theory of operation
The following sections discuss the theory of operation for the GC, the engineering
principles and the concepts used.
Note
See Section 1.7 for definitions of the terminology used in the following explanations.
1.5.1 Thermal conductivity detector
One of the detectors available on the 700XA is a thermal conductivity detector (TCD) that
consists of a balanced bridge network with heat sensitive thermistors in each leg of the
bridge. Each thermistor is enclosed in a separate chamber of the detector block.
One thermistor is designated the reference element and the other thermistor is
designated the measurement element. See Figure 1-2 for a schematic diagram of the
thermal conductivity detector.
Introduction
1
Analyzer assembly with TCD bridgeFigure 1-2:
5
Introduction
In the quiescent condition, prior to injecting a sample, both legs of the bridge are exposed
to pure carrier gas. In this condition, the bridge is balanced and the bridge output is
electrically nulled.
The analysis begins when the sample valve injects a fixed volume of sample into the
column. The continuous flow of carrier gas moves the sample through the column. As
successive components elute from the column, the temperature of the measurement
element changes.
The temperature change unbalances the bridge and produces an electrical output
proportional to the component concentration.
The differential signal developed between the two thermistors is amplified by the
preamplifier. Figure 1-3 illustrates the change in detector electrical output during elution of
a component.
Detector output during component elutionFigure 1-3:
In addition to amplifying the differential signal developed between the two thermistors,
the preamplifier supplies drive current to the detector bridge.
The signal is proportional to the concentration of a component detected in the gas
sample. The preamplifier provides four different gain channels as well as compensation for
baseline drift.
The signals from the preamplifier are sent to the electronic assembly for computation,
recording on a printer, or viewing on a PC monitor with MON2020.
6
Introduction
1.5.2 Flame ionization detector
The other detector available for the 700XA is the flame ionization detector (FID). The FID
requires a polarization voltage and its output is connected to the input to a high
impedance amplifier that is called an electrometer. The burner uses a mixture of hydrogen
and air to maintain the flame. The sample of gas to be measured is also injected into the
burner. See Figure 1-4 for a schematic diagram of the FID.
Analyzer assembly with FID detector bridgeFigure 1-4:
Introduction
1
1.5.3 Liquid sample injection valve
The optional liquid sample injection valve (LSIV) converts a liquid sample into a gas sample
for GC analysis.
7
Introduction
LSIV cross sectionFigure 1-5:
The LSIV penetrates the wall of the lower compartment and is held in place by a retaining
ring. The mounting arrangement is designed to ensure integrity of the flameproof
enclosure.
The outermost end houses an air-operated piston. Air at 60 PSI is directed by a solenoid
valve to either advance the stem to inject the sample or to retract the stem.
The next section houses sample input connections and stem sealing components. There
are two 1/8-inch O.D. tubing ports in this section; one port is for sample input, the other is
the exhaust for sample flow.
Within the enclosure cavity are the flash chamber components surrounded with insulating
covers. At working temperatures, the surfaces of these covers become very hot to the
touch.
The tip of the cylindrical flash chamber is the port where flashed sample is taken to the
oven system.
The port near the outer diameter of the end of the heated flash chamber block is the input
for carrier gas.
The flash chamber block is stainless steel and is surrounded by an insulating mounting
adapter. It houses the heater and an RTD.
1.5.4 Methanator
After all other components have been separated from the sample, carbon monoxide and
carbon dioxide, which are normally present in quantities too small to be detected by the
GC, can be sent through the optional methanator, where the two gases are combined with
hydrogen to make methane in a heat-generated catalytic reaction. The methanator is also
known as a methanizer or a catalytic converter.
8
Introduction
1.5.5 Data acquisition
Every second, exactly 50 equally spaced data samples are taken (i.e., one data sample
every 20 milliseconds) for analysis by the controller assembly.
As a part of the data acquisition process, groups of incoming data samples are averaged
together before the result is stored for processing. Non-overlapping groups of N samples
are averaged and stored, and thus reduce the effective incoming data rate to 40/N
samples per second. For example, if N = 5, then a total of 40/5 or 8 (averaged) data
samples are stored every second.
The value for the variable N is determined by the selection of a Peak Width parameter
(PW). The relationship is
N = PW
where PW is given in seconds. Allowable values of N are 1 to 63; this range corresponds to
PW values of 2 to 63 seconds.
The variable N is known as the integration factor. This term is used because N determines
how many points are averaged, or integrated, to form a single value. The integration of
data upon input, before storing, serves two purposes:
• The statistical noise on the input signal is reduced by the square root of N. In the
case of N = 4, a noise reduction of two would be realized.
• The integration factor controls the bandwidth of the chromatograph signal. It is
necessary to match the bandwidth of the input signal to that of the analysis
algorithms in the controller assembly. This prevents small, short-duration
perturbations from being recognized as true peaks by the program. It is therefore
important to choose a Peak Width that corresponds to the narrowest peak in the
group under consideration.
Introduction
1
1.5.6 Peak detection
For normal area or peak height concentration evaluation, the determination of a peak's
start point and end point is automatic. The manual determination of start and end points is
used only for area calculations in the Forced Integration mode. Automatic determination
of peak onset or start is initiated whenever Integrate Inhibit is turned off. Analysis is started
in a region of signal quiescence and stability, such that the signal level and activity can be
considered as baseline values.
Note
The controller assembly software assumes that a region of signal quiescence and stability will exist.
Having initiated a peak search by turning Integrate Inhibit off, the controller assembly
performs a point by point examination of the signal slope. This is achieved by using a
digital slope detection filter, a combination low pass filter and differentiator. The output is
continually compared to a user-defined system constant called Slope Sensitivity. A default
value of 8 is assumed if no entry is made. Lower values make peak onset detection more
sensitive, and higher values make detection less sensitive. Higher values (20 to 100) would
be appropriate for noisy signals, e.g. high amplifier gain.
9
Introduction
Onset is defined where the detector output exceeds the baseline constant, but peak
termination is defined where the detector output is less than the same constant.
Sequences of fused peaks are also automatically handled. This is done by testing each
termination point to see if the region immediately following it satisfies the criteria of a
baseline. A baseline region must have a slope detector value less than the magnitude of
the baseline constant for a number of sequential points. When a baseline region is found,
this terminates a sequence of peaks.
A zero reference line for peak height and area determination is established by extending a
line from the point of the onset of the peak sequence to the point of the termination. The
values of these two points are found by averaging the four integrated points just prior to
the onset point and just after the termination points, respectively.
The zero reference line will, in general, be non-horizontal, and thus compensates for any
linear drift in the system from the time the peak sequence starts until it ends.
In a single peak situation, peak area is the area of the component peak between the curve
and the zero reference line. The peak height is the distance from the zero reference line to
the maximum point on the component curve. The value and location of the maximum
point is determined from quadratic interpolation through the three highest points at the
peak of the discrete valued curve stored in the controller assembly.
For fused peak sequences, this interpolation technique is used both for peaks, as well as,
valleys (minimum points). In the latter case, lines are dropped from the interpolated valley
points to the zero reference line to partition the fused peak areas into individual peaks.
The use of quadratic interpolation improves both area and height calculation accuracy and
eliminates the effects of variations in the integration factor on these calculations.
For calibration, the controller assembly may average several analyses of the calibration
stream.
1.6 Basic analysis computations
Two basic analysis algorithms are included in the controller assembly:
• Area Analysis – calculates area under component peak
• Peak Height Analysis – measures height of component peak
Note
For additional information about other calculations performed, see the MON2020 user manual.
1.6.1 Concentration analysis - response factor
10
Concentration calculations require a unique response factor for each component in an
analysis. These response factors may be manually entered by an operator or determined
automatically by the system through calibration procedures (with a calibration gas mixture
that has known concentrations).
Introduction
The response factor calculation, using the external standard, is:
AR Fn=
Area
Cal
n
or
n
HR Fn=
H t
Cal
n
n
where
ARF
Area
Cal
Ht
n
HRF
n
n
n
n
area response factor for component “n” in area per mole percent
area associated with component “n” in calibration gas
amount of component “n” in mole percent in calibration gas
peak height associated with component “n” mole percent in calibration gas
peak height response factor for component “n”
Calculated response factors are stored by the controller assembly for use in the
concentration calculations, and are printed out in the configuration and calibration
reports.
Average response factor is calculated as follows:
k
∑
R F
i
RFAV Gn=
i=1
k
Introduction
1
where
RFAVG
n
RF
i
k number of calibration runs used to calculate the response factors
area or height average response factor for component “n”
area or height average response factor for component “n” from the calibration run
The percent deviation of new RF averages from old RF average is calculated in the following
manner:
R F
− R F
deviation =
new
R F
old
old
× 100
where the absolute value of percent deviation has been previously entered by the
operator.
1.6.2 Concentration calculation - mole percentage (without normalization)
Once response factors have been determined by the controller assembly or entered by the
operator, component concentrations are determined for each analysis by using the
following equations:
11
Introduction
CON Cn=
Area
AR F
n
or
n
CON Cn=
H t
HR F
n
n
where
ARF
n
Area
CONC
Ht
n
HRF
n
n
Area response factor for component “n” in area per mole percent.
Area associated with component “n” in unknown sample.
Concentration of component “n” in mole percent.
n
Peak height associated with component “n” mole percent in unknown sample.
Peak height response factor for component “n”.
Component concentrations may be input through analog inputs 1 to 4 or may be fixed. If a
fixed value is used, the calibration for that component is the mole percent that will be used
for all analyses.
1.6.3 Concentration calculation in mole percentage (with normalization)
The normalized concentration calculation is:
CON C
∑
i=1
k
CON C
n
× 100
i
CONC Nn=
where
CONCN
n
CONC
i
CONC
n
k Number of components to be included in the normalization.
Note
The average concentration of each component will also be calculated when data averaging is
requested.
1.7 Glossary
Auto Zero Automatic zeroing of the TCD preamplifier can be configured to take
Normalized concentration of component “n” in percent of total gas concentration.
Non-normalized concentration of component “n” in mole percent for each “k”
component.
Non-normalized concentration of component “n” in mole percent.
place at any time during the analysis if the component is not eluting or
the baseline is steady.The FID will auto zero at each new analysis run
12
Introduction
and can be configured to auto zero anytime during the analysis if the
component is not eluting or the baseline is steady. The TCD is only
auto zeroed at the start of a new analysis.
Baseline Signal output when there is only carrier gas going across the
detectors. In a chromatogram you should only see Baseline when
running an analysis without injecting a sample.
Carrier gas The gas used to push the sample through the system during an
analysis. In C6+ analysis we use Ultra Pure (zero grade) Carrier Gas for
the carrier. This gas is 99.995 percent pure.
Chromatogram A permanent record of the detector output. A chromatogram is
obtained from a PC interfaced with the detector output through the
controller assembly. A typical chromatogram displays all component
peaks, and gain changes. It may be viewed in color as it is processed
on a PC VGA display. Tick marks recorded on the chromatogram by
the controller assembly indicate where timed events take place.
Component Any one of several different gases that may appear in a sample
mixture. For example, natural gas usually contains the following
components: nitrogen, carbon dioxide, methane, ethane, propane,
isobutane, normal butane, isopentane, normal pentane, and hexanes
plus.
CTS Clear to send.
DCD Data carrier detect.
DSR Data set ready.
DTR Data terminal ready.
FID Flame ionization detector. The optional FID may be used in place of a
TCD for the detection of trace compounds. The FID requires a
polarization voltage and its output is connected to the input to a high
impedance amplifier, an electrometer. The sample of gas to be
measured is injected into the burner with a mixture of hydrogen and
air to maintain the flame.
LSIV Liquid sample injection valve. The optional LSIV is used to convert a
liquid sample to a gas sample by vaporizing the liquid in a heated
chamber, then analyzing the flashed sample.
Methanator The optional methanator, also known as a catalytic converter,
transforms otherwise undetectable carbon dioxide and/or carbon
monoxide into methane by adding hydrogen and heat to the sample.
Response factor Correction factor for each component as determined by the following
calibration:
RF =
Calibration Concentration
RawArea
Retention time Time, in seconds, that elapses between the start of analysis and the
sensing of the maximum concentration of each component by the
detector.
RI Ring indicator.
RLSD Received line signal detect. A digital simulation of a carrier detect.
RTS Request to send.
Introduction
1
13
Introduction
RxD, RD, or S
Receive data, or signal in.
in
TCD Thermal conductivity detector. A detector that uses the thermal
conductivity of the different gas components to produce an
unbalanced signal across the bridge of the preamplifier. The higher
the temperature, the lower the resistance on the detectors.
TxD, TD, or S
Transmit data, or signal out.
out
14
Equipment description and specifications
2 Equipment description and
specifications
Use the following sections to reference the 700XA equipment description or
specifications.
2.1 Equipment description
The 700XA consists of a copper-free aluminum explosion-proof chamber, and a front panel
assembly. The chamber is divided into two compartments that together house the GC’s
major components. This unit is designed for hazardous locations.
700XA gas chromatographFigure 2-1:
Equipment description and specifications
2
2.1.1 Front panel assembly
The front panel assembly is located on the front section of the lower enclosure and
consists of a removable, explosion-proof panel that shields either a switch panel or a local
operator interface (LOI).
15
Equipment description and specifications
The switch panel
The switch panel contains a network of on/off switches that allow you to manually control
the GC’s stream and analytical valves.
8-stream switch panel (left) and 18-stream switch panel (right)Figure 2-2:
There are two types of switch panels: 8-stream and 18-stream. The 8- stream switch panel
is the standard panel, and is used when the GC has only one heater/solenoid board
installed; if two heater/solenoid boards are installed, then the 18-stream switch panel is
used.
Valve switch from switch panel set to “OFF”Figure 2-3:
A valve has the following three operational modes:
• AUTO - The valve turns on and off according to the Timed Events table that is
accessible through MON2020. To set a valve to AUTO mode, set its switch on the
switch panel to the “up” position.
16
Equipment description and specifications
• OFF - The valve turns off and remains off until the operational mode is changed. To
set a valve to OFF mode, set its switch on the switch panel to the “center”
position—that is, the switch is neither flipped “up” nor “down”.
• ON - The valve turns on and remains on until the operational mode is changed. To
set a valve to ON mode, set its switch on the switch panel to the “down” position.
Equipment description and specifications
Status LEDs (Top of switch panel)Figure 2-4:
The switch panels also contain the following status lights that allow you to monitor the
GC’s condition:
• Working - Turns green when the GC is in analysis mode.
• Unack. Alarm - Turns yellow if there is an unacknowledged alarm.
• Active Alarm - Turns red if there is an active alarm.
FID/FPD Status LEDFigure 2-5:
2
• FID/FPD - The 18-stream switch panel contains a FID or FPD status LED that can
indicate the following:
- A green light means the flame has ignited.
- A flashing yellow light means an attempt is being made to ignite the flame.
- A red light means the flame as gone out or that the FID or FPD is over-
temperature.
17
Equipment description and specifications
• CPU - Green light blinks continuously while the GC is running.
• Valves - Turns green if the valves are functioning automatically; turns red if the
valves’ automatic settings have been overridden.
Note
During GC start up, all LEDs turn on for approximately ten seconds.
The local operator interface
The optional local operator interface (LOI) gives you more in-depth control over the GC’s
functions than does the switch panel. It has a high resolution color display that is touch key
activated and allows you to operate a 700XA GC without a laptop or a PC.
Status LEDs (Bottom of switch panel)Figure 2-6:
The local operator interfaceFigure 2-7:
The LOI includes the following features:
• Color LCD with VGA (640 x 480 pixels) resolution.
• ASCII text and graphics modes.
• Adjustable auto-backlighting.
18
Equipment description and specifications
• 8 infrared-activated touch screen keys that eliminate the requirement for a
magnetic pen.
• Complete GC status, control and diagnostics, including full chromatogram display.
See Appendix A for more information about operating the LOI.
Equipment description and specifications
2.1.2 Upper compartment
The upper compartment contains the following components:
• Valves. There are two types of XA valves: 6-port and 10-port. A 700XA can have a
maximum of four XA valves consisting of any combination of the two types.
• Column module. Either capillary or micro-packed.
• Thermal conductivity detector (TCD). The 700XA has a minimum of one TCD and a
maximum of two TCDs.
• Two heating elements: a “top hat” heater and a column heater.
• One temperature switch for each heating element. The switch turns off its
heating element if the heating element reaches 257° F (160° C).
• Pressure switch. The pressure switch activates when the carrier pressure falls below
a predetermined set point. When activated, the switch triggers a general alarm that
displays on the front panel or LOI and in MON2020.
• Flame ionization detector (FID). The optional FID, which detects trace levels of
hydrocarbons, can be used in place of one TCD.
• Flame photometric detector (FPD). The optional FPD, which detects trace levels of
sulphur compounds, can be used in place of a TCD. Installed as a "side car"
component. For more information, refer to the FPD for Gas Chromatographs
Hardware Reference Manual.
• Methanator. The methanator, or catalytic converter, is an optional component that
converts otherwise undetectable carbon dioxide and/or carbon monoxide into
methane by adding hydrogen and heat to the sample.
• Liquid sample injection valve (LSIV). The optional LSIV is used to vaporize a liquid
sample, thereby expanding the GC’s capability to measure liquids.
2
2.1.3 Lower compartment
The lower compartment consists of the following components:
• Backplane. The backplane is the GC’s central printed circuit board (PCB). Its main
function is as a connection point for the GC’s specialized plug-in PCBs. The
backplane also hosts connections for analog outputs and analog inputs, serial ports
and an Ethernet port.
• Card cage. The card cage holds the specialized PCBs that plug into the backplane.
The following PCBs are housed in the card cage:
- Preamp board
- CPU board
- Base I/O board
19
Equipment description and specifications
- Heater/Solenoid board
The card cage also has four additional slots for the following optional PCBs:
- A second preamp board
- A second heater/solenoid board
- Two optional communications boards
The explosion-proof housing should not be opened when the unit is exposed to an
explosive environment. If access to the explosion-proof housing is required, take
precautions to ensure that an explosive environment is not present. Failure to do so
may result in injury or death to personnel or cause damage to the equipment.
• Optional AC/DC power supply.
WARNING!
See power supply label prior to connection. Check the unit power design to determine if
it is equipped for AC or DC power. Applying 110/220 VAC to a DC power input unit will
severely damage the unit. Failure to do so may result in injury or death to personnel or
cause damage to the equipment.
WARNING!
Note
The 700XA CSA-certified unit is equipped with 3/4-inch NPT-thread adapters.
2.1.4 Mechanical pressure regulators
The mechanical pressure regulatorsFigure 2-8:
20
Equipment description and specifications
The mechanical pressure regulators and gauges are used to set and monitor the pressure
of the carrier gas flow through the GC's columns, as well as the pressure of the FID air and
fuel (H2).
The regulators and gauges are located beneath the GC.
2.2 Equipment specifications
2.2.1 Utilities
Use the following table to determine the utility specifications.
Type Specification
Unit dimensions
• Basic unit envelope
W - 15.2” (387 mm)
H - 41.5” (1054 mm)
D - 19.2” (488 mm)
• Wall mount
W - 18.2” (463 mm)
H - 41.5” (1054 mm)
D - 19.2” (488 mm)
• Pole mount
W - 18.2” (463 mm)
H - 41.5” (1054 mm)
D - 25.0” (635 mm)
• Floor mount
W - 18.2” (463 mm)
H - 58.0” (1470 mm)
D - 19.2” (488 mm)
Equipment description and specifications
2
Note
Allow 14” (360 mm additional) clearance for removal of dome.
Unit weight • Wall mount - 110 lbs (59 kg)
• Pole mount - 135 lbs (61 kg)
• Floor mount - 180 lbs (82 kg)
Tubing • 316 stainless steel
• 316 stainless steel and Kapton® in contact with sample
• Sulfinert® steel (optional)
21
Equipment description and specifications
Type Specification
Mounting • Floor mount
Power • 24V DC standard (21-30 V DC operating voltage range); MAX 150 watts
Instrument air Not required; optional for valve actuation, minimum pressure of 90 psig
Environment • Hazardous area certified: -20o C to 60o C (-4o F to 140o F)
Approvals
• Pole mount:
- 2” (60.3 mm)
- 3” (89.0 mm)
- 4” (114.3 mm)
• Direct wall mount
• (optional) 100-120/240 V AC; 50-60 Hz
Note
Voltage range includes line voltage variations.
• 0 to 95% RH (non-condensing)
• Indoor/outdoor
• Pollution - degree 2 (The unit can withstand some non conductive environ-
mental pollutants e.g., humidity.)
FOR USE IN HAZARDOUS LOCATIONS:
• For Canada: Class I, Zone 1, EX d IIC T6, Enclosure Type 4 Class I, Division 1,
Group B, C and D.
• For USA: Class I, Zone 1, EX d IIC T6, Enclosure Type 4 Class I, Division 1, Group
B, C and D.
2.2.2 Electronic hardware
Use the following table to determine the electronic hardware specifications:
Type Specification
Rating Division 1; no purge required
Communication
ports
Optional modem 56K Baud Telephone
3 configurable Modbus ports that support RS-232/422/485 protocols; 2 optional ports in expansion slots; 9-pin RS-232 port.
Note
The maximum number of simultaneous Modbus TCP/IP connections from
Modbus Master is 10.
22
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