Teledyne GC-Pro-TCD User Manual

INSTRUCTION, OPERATING AND

MAINTENANCE MANUAL FOR

GC-PRO TCD

P/N M89443

DATE 4/05/13

Toxic and/or flammable gases or liquids may be present in this monitoring system.
Personal protective equipment may be required when servicing this instrument.
Hazardous voltages exist on certain components internally which may persist for

a time even after the power is turned off and disconnected.
Only authorized personnel should conduct maintenance and/or servicing. Before

conducting any maintenance or servicing, consult with authorized
supervisor/manager.

Teledyne Analytical Instruments

DANGER

GC-Pro TCD

Copyright © 2013 Teledyne Analytical Instruments

All Rights Reserved. No part of this manual may be reproduced, transmitted, transcribed,
stored in a retrieval system, or translated into any other language or computer language in
whole or in part, in any form or by any means, whether it be electronic, mechanical,
magnetic, optical, manual, or otherwise, without the prior written consent of Teledyne
Analytical Instruments, 16830 Chestnut Street, City of Industry, CA 91748.

Warranty

This equipment is sold subject to the mutual agreement that it is warranted by us free from
defects of material and of construction, and that our liability shall be limited to replacing or
repairing at our factory (without charge, except for transportation), or at customer plant at
our option, any material or construction in which defects become apparent within one year
from the date of shipment, except in cases where quotations or acknowledgements provide
for a shorter period. Components manufactured by others bear the warranty of their
manufacturer. This warranty does not cover defects caused by wear, accident, misuse,
neglect or repairs other than those performed by Teledyne or an authorized service center.
We assume no liability for direct or indirect damages of any kind and the purchaser by the
acceptance of the equipment will assume all liability for any damage which may result from
its use or misuse.

We reserve the right to employ any suitable material in the manufacture of our apparatus,
and to make any alterations in the dimensions, shape or weight of any parts, in so far as
such alterations do not adversely affect our warranty.

Important Notice

This instrument provides measurement readings to its use r, an d serves as a tool b y whic h
valuable data can be gathered. The information provided by the instrument may assist the user
in eliminating potential hazards caused by his process; however, it is essential that all
personnel involved in the use of the instrument or its interface be properly trained in the
process being measured, as well as all instrumentation related to it.

The safety of personnel is ultimately the responsibility of those who control process
conditions. While this instrument may be able to provide early warning of imminent
danger, it has no control over process conditions, and it can be misused. In particular, any
alarm or control systems installed must be tested and understood, both as to how they
operate and as to how they can be defeated. Any safeguards required such as locks, labels,
or redundancy, must be provided by the user or specifically requested of Teledyne at the
time the order is placed.

Therefore, the purchaser must be aware of the hazardous process conditions. The purchaser
is responsible for the training of personnel, for providing hazard warning methods and
instrumentation per the appropriate standards, and for ensuring that hazard warning devices
and instrumentation are maintained and operated properly.

Teledyne Analytical Instruments, the manufacturer of this instrument, cannot accept
responsibility for conditions beyond its knowledge and control. No statement expressed or
implied by this document or any information disseminated by the manufacturer or its
agents, is to be construed as a warranty of adequate safety control under the user’s process
conditions.

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Safety Messages

Your safety and the safety of others are very important. We have
provided many important safety messages in this manual. Please read
these messages carefully.

A safety message alerts you to potential hazards that could hurt you
or others. Each safety message is associated with a safety alert symbol.
These symbols are found in the manual and inside the instrument. The
definition of these symbols is described below:

GENERAL WARNING/CAUTION: Refer to the
instructions for details on the specific danger. These
cautions warn of specific procedures which if not
followed could cause bodily Injury and/or damage the
instrument.

No

Symbol

CAUTION: HOT SURFACE WARNING: This warning is
specific to heated components within the instrument.
Failure to heed the warning could result in serious burns
to skin and underlying tissue.

WARNING: ELECTRICAL SHOCK HAZARD: Dangerous
voltages appear within this instrument. This warning is
specific to an electrical hazard existing at or nearby the
component or procedure under discussion. Failure to heed
this warning could result in injury and/or death from
electrocution.

Technician Symbol: All operations marked with this
symbol are to be performed by qualified maintenance
personnel only.

NOTE: Additional information and comments regarding
a specific component or procedure are highlighted in the
form of a note.

STAND-BY: This symbol indicates that the instrument is
on Stand-by but circuits are active.

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CAUTION: THE ANALYZER SHOULD ONLY BE USED FOR THE

PURPOSE AND IN THE MANNER DESCRIBED IN
THIS MANUAL.

IF YOU USE THE ANALYZER IN A MANNER OTHER
THAN THAT FOR WHICH IT WAS INTENDED,
UNPREDICTABLE BEHAVIOR COULD RESULT
POSSIBLY ACCOMPANIED WITH HAZARDOUS
CONSEQUENCES.

This manual provides information designed to guide you through the
installation, calibration and operation of your new analyzer. Please read
this manual and keep it available.

Occasionally, some instruments are customized for a particular
application or features and/or options added per customer requests.
Please check the front of this manual for any additional information in
the form of an Addendum which discusses specific information,
procedures, cautions and warnings that may be specific to your
instrument.

Manuals do get misplaced. Additional manuals can be obtained from
Teledyne at the address given in the Appendix. Some of our manuals are
available in electronic form via the internet. Please visit our website at:
www.teledyne-ai.com.

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Additional Safety Information

DANGER

COMBUSTIBLE GAS USAGE

This is a general purpose instrument designed for use in a
non-hazardous area. It is the customer's responsibility to
ensure safety especially when combustible gases are being
analyzed since the potential of gas leaks always exist.

WARNING

The customer should ensure that the principles of operating
of this equipment are well understood by the user. Misuse of
this product in any manner, tampering with its components,
or unauthorized substitution of any component may
adversely affect the safety of this instrument.

Since the use of this instrument is beyond the control of
Teledyne, no responsibility by Teledyne, its affiliates, and
agents for damage or injury from misuse or neglect of this
equipment is implied or assumed.

WARNING: If toxic or flammable gases are used, always purge

the entire system before performing any
maintenance and always leak check the system after
removing any tubing or fittings on the sample
system. See the procedures for purging and leak
checking this instrument on the following pages.

If toxic gases or other hazardous materials are
introduced into the sample system, the same
precautions regarding leak checking and purging
apply to the sample lines and sample supply or
delivery lines.

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WARNING: ELECTRICAL SHOCK HAZARD.

ONLY AUTHORIZED AND SUITABLY TRAINED
PERSONNEL SHOULD PERFORM WORK INSIDE OF
THE INSTRUMENT. COMPONENTS WITHIN THE
COVER, INSIDE THE ISOTHERMAL CHAMBER
(SAMPLE SYSTEM), AND ON PC BOARDS MAY
CONTAIN DANGEROUSLY HIGH VOLTAGE
SUFFICIENT TO CAUSE SERIOUS INJURY OR
DEATH.

There are the following three types of inaccessible

shock hazards within the Analyzer:

1. Line voltages and line related voltages such as
115 VAC which exists within the 230 VAC
versions as well. These voltages stop when the
Analyzer is turned off and the mains (line) cord is
removed from the instrument.

2. External hazardous voltages which may be
connected to the Analyzer alarm relay
connections.

WARNING: THIS INSTRUMENT IS DESIGNED TO BE OPERATED

IN A NONHAZARDOUS AREA. DEPENDING ON THE
APPLICATION, TOXIC GASES OR
FLAMMABLE/EXPLOSIVE GASES MAY BE
PRESENT. IT IS THEREFORE, THE CUSTOMER'S
RESPONSIBILITY TO ENSURE THAT PROPER
TRAINING AND UNDERSTANDING OF THE
PRINCIPLES OF OPERATION OF THIS EQUIPMENT
ARE UNDERSTOOD BY THE USER. SINCE THE USE
OF THIS INSTRUMENT IS BEYOND THE CONTROL
OF TELEDYNE, NO RESPONSIBILITY BY TELEDYNE,
ITS AFFILIATES AND AGENTS FOR DAMAGE OR
INJURY RESULTING FROM MISUSE OR NEGLECT
OF THIS INSTRUMENT IS IMPLIED OR ASSUMED.
MISUSE OF THIS PRODUCT IN ANY MANNER,
TAMPERING WITH ITS COMPONENTS OR
UNAUTHORIZED SUBSTITUTION OF ANY
COMPONENT MAY ADVERSELY AFFECT THE
SAFETY OF THIS INSTRUMENT.

CAUTION: WHEN OPERATING THIS INSTRUMENT, ALL

COVERS SECURELY FASTENED. THE GAUGES

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MUST BE IN PROPER WORKING ORDER. DO NOT
OVERPRESSURIZE THE SYSTEM.

READ THIS MANUAL BEFORE OPERATING THE

INSTRUMENT AND ADHERE TO ALL WARNINGS
INCLUDED IN THIS MANUAL.

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Table of Contents

Safety Messages .......................................................................... iii

Additional Safety Information ...................................................... v

List of Figures ............................................................................. xii

List of Tables .............................................................................. xiii

Introduction ................................................................................... 1

1.1 Main Features of the Analyzer 1

1.2 Principle of Operation 3

1.3 Analyzer Description 3

1.4 Applications 7

Operational Theory ....................................................................... 9 

2.1 Introduction 9

2.2 Modes of Operation 10

2.3 Analyzer Subsystems 11

2.3.1 Sample System 11

2.3.2 Gas Flow Control System 12

2.3.3 Gas Separation System 14

2.4 Detector Cell 14

Installation ................................................................................... 17

3.1 Unpacking the Analyzer 17

3.2 Mounting the Analyzer 17

3.3 User Connections 18

3.3.1 Electrical Power Connections 18

3.3.2 Electronic Connections 18

3.3.2.1 Primary Input Power 19

3.3.2.2 Fuse Installation 20

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3.3.2.3 50-Pin Equipment Interface Connector 20

3.3.2.4 Analog Output 20

3.3.2.5 Alarm Relays 22

3.3.2.6 Digital Remote Cal Inputs 24

3.3.2.7 ‘Measure Once’ (or one shot measurement)
contacts 25

3.3.2.9 Pin Out Table 25

3.3.2.10 RS-232 Port 28 

3.3.3 Gas Connections 29

3.3.3.1 Effluent 31

3.3.3.2 Sensor Vent 31

3.3.3.3 Carrier Gas Connection 31

3.3.4 Sample and Span Gas Connections 31

3.4 Placing the System in Operation 32

Operation ..................................................................................... 33

4.1 Equipment 34

4.2 Preliminary Power-Off Check List 34

4.3 Powering Up the Unit 35

4.4 Activating the Support Gases 38

4.4.1 Carrier Gas 38

4.4.2 Span Gas 38

4.5 Analyzer Operation 38

4.5.1 Default Parameters 39

4.5.2 The HOME Screen 40

4.5.3 The MENU Screen 41

4.5.4 Standby 42

4.5.5 Overlay Chromatogram 44

4.5.6 Timing 46

4.5.6.1 TCD Amplifier Gain 50

4.5.7 Temperature 50

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4.5.7.1 Thermocouple 51

4.5.7.2 Settings 52

4.5.7.3 PID Settings 53

4.5.7.4 Status 54

4.5.8 Group Setup 55

4.5.9 Analog Adjust 58

4.5.10 Calibration 59

4.5.10.1 Span 60

4.5.10.2 Alt Span 62

4.5.10.3 Auto cal 65

4.5.11 Self Test 66

4.5.12 Settings 68

4.5.12.1 Alarms 69

4.5.12.2 Range 72

4.5.12.3 Change Stream 74

4.5.12.4 Time 75 

4.5.12.5 Password 76

4.5.12.6 Communication 76

4.5.12.7 Detector 78

4.5.12.8 Set TCD 79

4.5.12.9 Cycle Mode 80

4.5.13 Analysis Mode 80

4.5.13.1 T-Time 81

4.5.13.2 T_Cycle 82

4.5.13.3 Chromatogram 83

4.5.13.4 VS Count 85

4.5.13.5 Cold Boot 85

Maintenance & Troubleshooting ................................................ 89

Appendix ...................................................................................... 91

A.1 Specifications and Initial Settings: 91

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A.2 Recommended Spare Parts List 92
A.3 Drawing List 93

Appendix B .................................................................................. 95

B1. VNC for GC-Pro TCD 95

Appendix C ................................................................................ 101

C1 Addendum and Testing Results 101

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List of Figures

Figure 1-1: GC-Pro TCD Front Panel .............................................. 4

Figure 1-2: GC-Pro TCD Rear Panel .............................................. 5

Figure 1-3: Internal PCB Arrangement ............................................ 6

Figure 1-4: GC-Pro TCD Internal View ............................................ 6

Figure 2-1: Internal Temperature Controllers ................................ 12

Figure 2-2: Typical Piping Diagram Used in the GC-Pro TCD ....... 13

Figure 2-3: Thermal Conductivity Cell Operating Principle ............ 14

Figure 3-1: GC-Pro TCD Rear Panel with Optional Gas Manifold . 19

Figure 3-2: Equipment Interface Connector Pin Arrangement....... 20



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List of Tables

Table 3-1: Analog Output Connections — Middle Connector ........ 21

Table 3-2: Analog Concentration Output—Example ...................... 22

Table 3-3: Alarm Relay Contact Pins — Top Connector ............... 23

Table 3-4: Remote Calibration Connections — Bottom Connector 24

Table 3-5: ‘Measure Once’ Relay Connections ............................. 25

Table 3-6: Pin out of Alarm Relay O/P (Top) 50 pin D-Sub

Connector .................................................................... 26 

Table 3-7: Pin out of Analog Signal (Middle) 50 pin D-Sub

Connector .................................................................... 26 

Table 3-8: Pin out of Standard (Bottom) 50 pin D-Sub Connectors27

Table 3-9: Commands via RS-232 Input ....................................... 28

Table 3-10: Required RS-232 Options .......................................... 28

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GC-Pro TCD Introduction

Introduction

The GC-Pro TCD Analyzer is a microprocessor controlled digital
instrument incorporating a Thermal Conductivity Detector (TCD)
coupled with a gas separation column and switching valve designed to
measure the quantity of aromatic hydrocarbons present in a positive
pressure sample gas. Up to 8 channels of output are present for
measuring specific analytes in a sample stream. In using a thermal
conductivity detector after gas separation through a column, the range of
analysis is extended to include additional phase separable inert, or other
difficult to analyze gas phase components like N2, H2. etc. that are
present in a positive pressure sample gas.

The GC-Pro TCD Analyzer has multiple channels for measurement
with enhanced versatility and capabilities. Due to its flexibility, it is
vitally important that you refer to Appendix C for the specific factory
setup for your application.

The GC-Pro TCD features a modern user interface with a touch
screen front panel facilitating operation, calibration, data collection and
display. With the Ethernet connectivity feature, this new interface allows
the instrument to be operated remotely with a VNC software application
from another digital device whereby the analyzer can be accessed,
controlled, data displayed etc. as if the analyzer were physically present.

Although the analyzer arrives already setup for your specific
application, a gas chromatograph mode allows the user to program the
instrument for measuring different species present in the sample.

1.1 Main Features of the Analyzer

The GC-Pro TCD Analyzer is sophisticated yet simple to use. A
touch screen display on the front panel provides access all phases of
setup, calibration, operation, and troubleshooting on the GC-Pro TCD.

The main features of the analyzer include:

 Stable, accurate thermal conductivity detector for analyzing

inert gases and other species not amenable to flame
ionization detection.

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Introduction GC-Pro TCD

 Data acquisition and control functions supporting:

 Pressure measurements, 5-Channels (Future option)
 Flow (MFC) measurements, 3-Channels (Future option)
 Oxygen measurements, 6-Channels (Future option)
 Temperature measurements and control, 4-Channels
 6-Channel Dew point Hygrometer measurements, 6-

Channel (Future option)

 Relay, (10) and solenoid outputs, (4)
 Alarm, (3) and over range indication outputs, (4)
 4-20mA current loop outputs, 10 channels
 HMI through Maple touch sensitive display

 The system operates at single phase AC, 110 or 220V 50/60

Hz (select at time of order).

 High resolution, accurate readings of concentration.
 Versatile analysis with three user-definable analysis ranges.
 Microprocessor based electronics: 8-bit CMOS

microprocessor with 32 kB RAM and 128 kB ROM.

 Auto ranging allows analyzer to automatically select the

proper preset range for a given measurement. Manual
override allows the user to lock onto a specific range of
interest.

 Two adjustable concentration alarms and a system failure

alarm.

 Extensive self-diagnostic testing at startup and on demand

with continuous power supply monitoring.

 RS-232 serial digital port for use with a computer or other

digital communication device.

 8-Analog outputs for concentration and range identification

(0-1 VDC standard and isolated 4-20 mA dc).

 Superior Accuracy

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1.2 Principle of Operation

The analyzer uses a sample valve which is a specialized electronic­controlled valve responsible for extracting a precise volume of sample
and delivering it to the separation column. This valve uses four micro
cavities and rotates between two positions in a timed fashion controlled
by the timing function in the control section.

The gas separation column separates the component of interest in the
sample gas based on its retention time in the packed column. Using a
carrier gas and a microprocessor actuated switching valve, the eluted gas
is analyzed using a Thermal Conductivity Detector (TCD). After each
injection cycle the column is back flushed to accept the fresh sample in
the next cycle. The result is a series of peaks over time corresponding to
the detector output for each sample cycle. The integrated area under the
peak is directly related to concentration and after signal processing, this
result is displayed in the appropriate units on the screen. The screen is
updated after each cycle.

1.3 Analyzer Description

The standard analyzer is a rack mountable instrument designed to fit
into a standard 19” instrument rack. The front interface screen is
mounted on the left side of the panel. The right side of the panel
includes the gas controls, pressure gauges and flowmeter. The front
panel is shown in Figure 1-1.

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Introduction GC-Pro TCD

Figure 1-1: GC-Pro TCD Front Panel

Gas pressure gauges and controls are mounted on the front panel
adjacent to the touch screen (human/machine interface abbreviated as
HMI) display as shown in Figure 1-1.

At the rear of the instrument are ports for the introduction of air,
zero, span, and sample gas as well as vent port connections. Three 50­pin user-interface cable connectors route input/output and alarm signals
to external devices. RS232 and a network port are also available at the
rear panel for connection to a remote computer or other digital
communication device. Internally, there are two USB user connections
which are used for updating firmware to the PCBs. Figure 1-2 shows the
rear panel including the user connections.

The analyzer is set up for either 120 VAC 60 Hz or 230 50/60 Hz
operation depending on the customer’s requirements. The appropriate
power cord for your unit is included with the analyzer.

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GC-Pro TCD Introduction

Figure 1-2: GC-Pro TCD Rear Panel

Internally, there are three isothermal chambers each separately
controlled for precise control and separation of analyzed species. In the
electronics section, internal PC boards are stacked in an assembly in an
order based on inter connectivity needs between the PCBs as well as
their association with other sub assemblies distributed within the system.
See Figure 1-3.

Following is the card stack-up from top to bottom planned inside the
system

 Heater card
 9261 controller card
 Analog data acquisition card
 Analog signal conditioning card
 89C5131 controller card

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Introduction GC-Pro TCD

Figure 1-3: Internal PCB Arrangement

Figure 1-4: GC-Pro TCD Internal View

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GC-Pro TCD Introduction

1.4 Applications

 Monitoring the benzene concentration of carbon dioxide gas

for use in the beverage industry.

 Monitoring aromatic contamination in air liquefaction and

other gas production processes.

 Gas purity certification.
 Detecting trace benzene in ambient air.
 Detecting atmospheric pollutants.

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Operational Theory

2.1 Introduction

The GC-Pro TCD Analyzer uses a Thermal Conductivity (TC)
Detector and a Gas Chromatograph (GC) Column to separate and
analyze different factions of a volatile hydrocarbon sample. Using a
carrier gas and a microprocessor actuated switching valve, a fixed
volume of sample is pushed into the column maintained at a constant
temperature. The eluted gas is analyzed for the specific components
configured for your application using the TC detector and the column is
back flushed to accept the fresh sample for the next cycle. Actual
separating and detecting sequence may vary depending on compounds
of interest in the application for which the analyzer is configured.

The GC-Pro TCD Analyzer uses the thermal conductivity detector to
sense a variety of components that are separated through a column and
eluted to the sensor in a time sequence determined by their respective
retention time. It compares the difference in conductivity between a
known volume of injected sample driven by carrier gas at a fixed
temperature to a constant flowing reference gas. Thermal conductivity is
a fast, accurate and reproducible tool for detection and measurement
under certain conditions. In general, thermal conductivity measurements
are binary and non-specific in nature, that is, they respond to the total
difference in thermal conductivity between two samples. If the sample
contains more than two components, the thermal conductivity
measurement is ill defined and cannot be used to determine the
concentration of the mixture without extensive calibration. Similarly, if
the thermal conductivity difference between components of a binary
mixture is low, sensitivity is negatively impacted.

The GC-Pro TC Analyzer avoids these issues by coupling the TC
detector with a gas separation capability in the GC column. Therefore,
even if the sample stream contains more than one compound, at any time
during analysis only a binary mixture which includes the component of
interest based on its separation properties, plus carrier gas is delivered to
the detector. A suitable carrier gas can be selected that among other
properties, maximizes the thermal conductivity difference for enhanced

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Operational Theory GC-Pro TCD

sensitivity. And since the sampling valve is designed to inject a precise
and known volume of sample at a fixed temperature, the actual
concentration of the compound of interest can be determined.

A stainless steel packed column containing Chromosorb Diatomite
or other material depending on the application, is held at a constant
temperature. The temperature as well as the carrier gas and its pressure
are critical and depend on the application. The actual temperature
setpoint and compound separation for your instrument have been
determined at the factory. They are listed in the Addendum and Testing
Results section of Appendix C.

Using a specific carrier gas to inject the sample gas into a known in
volume, the specific component of interest elutes from the column
within a few minutes. The exact timing is characteristic of the material
and has been determined at the factory during testing. Additionally, a
clear separation is observed from other components in the sample gas
however each has a characteristic timing so the instrument can select
only the peak associated with the compound of interest for processing.
All necessary information regarding carrier gas type, sample loop
volume, temperature and pressure settings, and internal timing settings
are given in the Addendum and Testing Results section of Appendix C.

2.2 Modes of Operation

The analyzer has 2 modes of operation depending on the position of
the GC Sampling Valve (See Piping Diagram in Figure 2-2). They are:
Sample Mode (position A) and Analysis Mode (position B).

1. Valve Position A—Sampling Mode

In this mode the analyzer configures the operational valve to
back flush the column and charge the sample loop. The Sample
Mode is programmed to continue for a 7 minute period by
factory default; however, it is usually modified to match the
needs of a particular process. The specific timing interval for
your system is listed in the Addendum and Testing Results
section of Appendix C. It is possible to set the Sample Mode
duration up to 25 minutes.

2. Valve Position B—Analysis Mode

In this mode the analyzer configures the sampling valve to feed
the gas in the sample loop through the column and to the
detector. The eluted sample from the column is fed to the TC

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GC-Pro TCD Operational Theory

detector for the analysis of the compound of interest in the
stream. If configured to do so, the analyzer may read the detector
for a programmed 5 second period at some point within this
mode cycle to obtain a baseline reading for further calculation.
This mode is usually programmed to continue until the
compound of interest is fully eluted from the column. It is
possible to set it up to 25 minutes.

During the Analysis Mode, a ‘Peak Detect’ period is programmed at
which time the analyzer reads the detector output. The analyzer
integrates the peak area during this time in conjunction with the baseline
settings to calculate the concentration of the compound of interest. The
calculation is performed at the end of the ‘Peak Detector’ period and the
result is displayed at the end of Analysis Mode.

2.3 Analyzer Subsystems

The Model Analyzer is composed of four subsystems:

1. Sample System

2. GC Column

3. Detector Cell

4. Electronic Signal Processing, Display and Control

2.3.1 Sample System

All components used to control the sample and supporting gases are
located on the front panel or inside the analyzer chassis. For the internal
components, they are accessible after removing the top cover of the
analyzer. Adjustments are made to the carrier gas pressure and sample
flow using the controls on the front panel. See Figure 1-1. Other
adjustments are made using the touch screen and are described in
Section 4.

The analyzer contains three separate isothermal chambers
‘SAMPLE’, ‘Sensor’, and ‘COLUMN’ that are controlled individually.
Temperature and control information are available onscreen. See Section

4.5.7. The chambers and the switching valve are identified in Figure 2-

1.

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Operational Theory GC-Pro TCD

Figure 2-1: Internal Temperature Controllers

The sample chamber contains the 10-port GC switching valve and 2
sample loops. The ‘TC Sensor’ chamber contains the thermal
conductivity sensor. The ‘COLUMN’ is housed in a separate
‘COLUMN’ enclosure and maintained at a temperature of 70° C.
Chamber temperatures have been set at the factory however they can be
changed by the user from the Settings/Thermocouple/Settings screen as
described in Section 4.5.7.2. The actual temperature setpoint for your
instrument may be different depending on the application. It is listed in
the Addendum and Testing Results section of Appendix C.

2.3.2 Gas Flow Control System

The analyzer is equipped with ports for the introduction of carrier
gas, span, and sample gas. Depending on the application and the options
chosen, some instruments may have a separate port for admitting a purge
gas.

It is imperative that the sample, carrier and span gases be supplied at
constant pressure using two stage stainless steel diaphragm gas
regulators. The recommended pressure range is 30 to 80 psig for sample
and carrier gas; the span gas should be supplied at a pressure of 20 psig

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GC-Pro TCD Operational Theory

to the restrictor fitting either on the optional auto calibration module or
the span inlet on the rear panel.

The Piping Diagram for the standard instrument is shown in Figure
2-2. A 10-port 2-position GC sampling valve is used to control and
direct gas flows including sampling, back flush, and carrier gas. The
fixed volume sample loop ensures the same volume of sample injection
in the column every cycle.

Figure 2-2: Typical Piping Diagram Used in the GC-Pro TCD

If your instrument is fitted with the optional auto calibration module,
a separate compartment containing of a pair of solenoid valves is
installed for controlling the introduction of sample or span gas to the
detector. Calibration can be performed automatically on a programmed
schedule or manually using the front panel interface.

Other detector options are available for the GC-Pro series instrument
which may alter the appearance of the front and rear panels and include
additional gas ports such as fuel and air for the FID option. These
options, if included, will be described in an accompanying addendum to
this manual.

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Operational Theory GC-Pro TCD

2.3.3 Gas Separation System

The carrier gas pressure and column temperature are the critical
parameters in the separation process. A heater is used in column housing
and the temperature controlled by the Temperature PCB. A constant
carrier gas flow is provided by a pressure regulator on the front panel set
to a specific pressure with an inlet carrier gas supply of 80 psig at the
rear panel. Thus, a stable flow is achieved by maintaining a constant
pressure across restrictors upstream from the cell. Actual carrier gas
flow rate through the column, which is crucial for separation retention
time, will depend on the carrier gas pressure and the type of column
used for each application. It is important that all temperature and
pressure settings are set to the values listed in the Addendum and Testing
Results section of Appendix C.

2.4 Detector Cell

The thermal conductivity sensor contains two chambers, one for the
reference gas of known conductivity (which is of the same as the carrier
gas) and one for the sample gas which is driven by the carrier gas. Each
chamber contains a pair of heated filaments. Depending on its thermal
conductivity, each of the gases conducts a quantity of heat away from the
filaments in its chamber. See Figure 2-3(a).

The resistance of the filaments depends on their temperature. These
filaments are parts of the two legs of a bridge circuit that unbalances if
the resistances of its two legs do not match. See Figure 2-1(b).

Figure 2-3: Thermal Conductivity Cell Operating Principle

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GC-Pro TCD Installation

Installation

Installation of the GC-Pro TCD Analyzer includes:

1. Unpacking

2. Mounting

3. Gas connections

4. Electrical connections

5. Testing the system.

3.1 Unpacking the Analyzer

Although the analyzer is shipped with all the materials you need to
install and prepare the system for operation. Carefully unpack the
analyzer and inspect it for damage. Immediately report any damage or
shortages to the shipping agent.

3.2 Mounting the Analyzer

The GC-Pro TCD analyzer is a general-purpose analyzer and as such
is designed with (non-sealed) enclosures. It must be installed in an area
where the ambient temperature is not permitted to drop below 32ºF or
rise above 100ºF. In areas outside these temperatures, auxiliary
heating/cooling must be supplied. The enclosure is oil and dust resistant
and although it is designed to resist moisture, it should NOT be
considered completely watertight. Mounting must be made securely.
Avoid locations that are subject to extreme vibration and sway.

Sufficient space must be provided around and above the analyzer to
accommodate the necessary electrical conduit and plumbing connections
and top cover removal. The top cover must be allowed to be lifted off for
possible service access to all components within the enclosure. Refer to
the sys t e m / a n a l yzer outline drawings for dimensions.

Regardless of configuration, the analyzer/system must be installed
on a level surface with sufficient space allocated on either side for

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Installation GC-ProTCD

personnel and test equipment access. Subject to the foregoing, the
analyzer should be placed as close to the sample point as is possible.

All pertinent dimensions, connecting points, and piping details can
be found in the drawings section as part of the outline, input-output, and
piping diagrams. These drawings are specific to the instrument or
system to which the manual applies.

3.3 User Connections

All user connections are made on the rear panel. Consult the input­output and outline diagrams in the drawing section of the manual. Not
all the features displayed may be present in your system. Optional
features when installed may change the appearance of the front and rear
panels as well as add details to some display screens. Refer to any
Addenda for additional information that may apply to your instrument.

3.3.1 Electrical Power Connections

The standard analyzer requires a supply of 100-125VAC, single­phase power. Power connections are made at the rear panel of the unit.
Refer to the input-output diagram for more information. The electrical
power service must include a high-quality ground wire. A high-quality
ground wire is a wire that has zero potential difference when measured
to the power line neutral. If you have the 220 VAC option, you will
require 220 or 240 VAC, 50/60 Hz power. Check the analyzer input­output diagram, power schematic, outline, and wiring diagrams for
incoming power specifications and connecting points.

CAUTION: PRIMARY POWER TO THE SYSTEM SHOULD NOT

BE SUPPLIED UNTIL ALL CUSTOMERS WIRING IS
INSPECTED PROPERLY BY START-UP PERSONNEL.

3.3.2 Electronic Connections

Figure 3-1 shows the GC-Pro TCD rear panel. There are connections
for power, digital communications, and both digital and analog
concentration output.

For safe connections, no uninsulated wiring should be able to come
in contact with fingers, tools or clothing during normal operation.

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CAUTION: USE SHIELDED CABLES. ALSO, USE PLUGS THAT

PROVIDE EXCELLENT EMI/RFI PROTECTION. THE
PLUG CASE MUST BE CONNECTED TO THE CABLE
SHIELD, AND IT MUST BE TIGHTLY FASTENED TO
THE ANALYZER WITH ITS FASTENING SCREWS.
ULTIMATELY, IT IS THE INSTALLER WHO ENSURES
THAT THE CONNECTIONS PROVIDE ADEQUATE
EMI/RFI SIELDING.

Figure 3-1: GC-Pro TCD Rear Panel with Optional Gas Manifold

3.3.2.1

PRIMARY INPUT POWER

The power cord receptacle and fuse block are located in the same

assembly. Insert the power cord into the power cord receptacle.

CAUTION: POWER IS APPLIED TO THE INSTRUMENT'S

CIRCUITRY AS LONG AS THE INSTRUMENT IS
CONNECTED TO THE POWER SOURCE.

The standard power supply requires 110 VAC, 50/60 Hz or 220

VAC, 50/60 Hz (optional) power.

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3.3.2.2 FUSE INSTALLATION

The fuse block, at the right of the power cord receptacle, accepts US
or European size fuses. A jumper replaces the fuse in whichever fuse
receptacle is not used.

3.3.2.3 50-PIN EQUIPMENT INTERFACE CONNECTOR

There are three 50-pin Equipment Interface Connectors installed on
the rear panel of the GC-Pro TCD. Figure 3-2 shows the pin layout of
the Equipment Interface connectors. The arrangement is shown as seen
when the viewer faces the rear panel of the analyzer. The pin numbers
for each input/output function are given where each function is
described in the paragraphs below.

Figure 3-2: Equipment Interface Connector Pin Arrangement

From top to bottom the signals handled by the individual connectors
are as follows:

 Top connector: Alarm relay connections
 Middle connector: Analog output signals
 Bottom connector: Standard connector for all additional

signals

See Section 3.3.2.9 for Pin-Out connections for each connector.

3.3.2.4 ANALOG OUTPUT

There are four DC output signal pins—two pins per output. These
are found on the middle connector. For polarity, see Table 3-1. The
outputs are:

0–1 VDC % of Range: Voltage rises linearly with increasing

concentration, from 0 V at 0
concentration to 1 V at full scale. (Full
scale = 100% of programmable range.)

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0–1 VDC Range ID: 0.20 V = Low Range

0.5 V = Medium Range

0.80 V = High Range

4–20 mA DC % Range: Current increases linearly with

concentration, from 4 mA at 0
concentration to 20 mA at full scale.
(Full scale = 100% of programmable
range.)

4–20 mA dc Range ID: 6.8 mA = Range 1

12.0 mA = Range 2

16.8 mA = Range 3

Table 3-1: Analog Output Connections — Middle Connector

Pin Function
3 Channel 2, + 4-20 mA, floating
4 Channel 2, – 4-20 mA, floating
5 Channel 1, + 4-20 mA, floating
6 Channel 1, – 4-20 mA, floating
8 Channel 2, 0-1 VDC
23 Channel 2, 0-1 VDC, negative ground
24 Channel 1, 0-1 VDC
7 Channel 1, negative ground

Examples:

The analog output signal has a voltage which depends on gas
concentration relative to the full scale of the range. To relate the signal
output to the actual concentration, it is necessary to know what range the
instrument is currently on, especially when the analyzer is in the auto
ranging mode.

The signal output for concentration is linear over the currently
selected analysis range. For example, if the analyzer is set on a range
that was defined as 90-100% nitrogen then the output would be as
shown in Table 3-2.

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Table 3-2: Analog Concentration Output—Example

% Voltage Signal Current Signal
Nitrogen Output (VDC) Output (mA DC)

90 0.0 4.0
91 0.1 5.6
92 0.2 7.2
93 0.3 8.8
94 0.4 10.4
95 0.5 12.0
96 0.6 13.6
94 0.7 15.2
98 0.8 16.8
99 0.9 18.4
100 1.0 20.0

3.3.2.5

ALARM RELAYS

The nine alarm-circuit connector pins connect to the internal alarm
relay contacts. The pins for the alarm relays are available from the top
interface connector. Each set of three pins provides one set of Form C
relay contacts. Each relay has both normally open and normally closed
contact connections. The contact connections are shown in Table 3-3.
They are capable of switching up to 3 amperes at 250 VAC into a
resistive load. The connectors are:

Threshold Alarm 1:

 Can be configured as high (actuates when

concentration is above threshold), or low (actuates
when concentration is below threshold).

 Can be configured as failsafe or non-failsafe
 Can be configured as non-latching
 Can be configured out (defeated).

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Threshold Alarm 2:

 Can be configured as high (actuates when

concentration is above threshold), or low (actuates
when concentration is below threshold).

 Can be configured as failsafe or non-failsafe
 Can be configured as non-latching
 Can be configured out (defeated).

System Alarm:

 Actuates when DC power supplied to circuits is

unacceptable in one or more parameters. Permanently
configured as failsafe and latching. Cannot be
defeated.

Note: Reset by pressing the STANDBY button to remove power.

Then press STANDBY again and any other button except
SYSTEM to resume. Further detail can be found in
Chapter 4, Section 4.5.4.

Table 3-3: Alarm Relay Contact Pins — Top Connector

Pin Contact
45 Threshold Alarm 1, normally closed contact
28 Threshold Alarm 1, moving contact
46 Threshold Alarm 1, normally open contact
42 Threshold Alarm 2, normally closed contact
44 Threshold Alarm 2, moving contact
43 Threshold Alarm 2, normally open contact
36 System Alarm, normally closed contact
20 System Alarm, moving contact
37 System Alarm, normally open contact

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Installation GC-ProTCD

3.3.2.6 DIGITAL REMOTE CAL INPUTS

The digital remote calibration signals are available on the bottom
connector. They input accepts 0 V (off) or 24 VDC (on) for remote
control of calibration. (See Remote Calibration Protocol below.) See
Table 3-4 for pin connections.

Span: Floating input. A 5–24 V input across the + and – pins puts the

analyzer into the Span mode If cycle mode is ‘Continuous’. Either
side may be grounded at the source of the signal. A 0–1 volt across
the terminals allows Span mode to terminate when done. A
synchronous signal must open and close external span valve
appropriately.

Cal Contact: This relay contact is closed while analyzer is spanning.
(See Remote Calibration Protocol below.)

Table 3-4: Remote Calibration Connections — Bottom Connector

Pin Function

10 + Remote Span
12 – Remote Span
40 Cal Contact
41 Cal Contact

Remote Calibration Protocol: To properly time the Digital Remote Cal
Inputs to the GC-Pro TCD Analyzer, the customer's controller must
monitor the Cal Relay Contact.

When the contact is OPEN, the analyzer is analyzing, the
Remote Cal Inputs are being polled, and a span command can be
sent.

When the contact is CLOSED, the analyzer is already calibrating. It
will ignore your request to calibrate, and it will not remember that
request.

Once a span command is sent, and acknowledged (contact closes),
release it. If the command is continued until after the span is complete,
the calibration will repeat and the Cal Relay Contact (CRC) will close
again.

For example:

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GC-Pro TCD Installation

1. Test the CRC. When the CRC is open, send a span command

until the CRC closes (The CRC will quickly close.)

2. When the CRC closes, remove the span command.

When CRC opens again, the span calibration is done, and the sample

is being analyzed.

3.3.2.7 ‘MEASURE ONCE’ (OR ONE SHOT MEASUREMENT) CONTACTS

There are three dedicated relay contacts and these are available from
the bottom Equipment Interface Connector. They are assigned to
indicate status of ‘measure once’ (or one shot measurement). Contacts
are normally open, and they close when GC-Pro TCD switches to that
particular range.

Table 3-5: ‘Measure Once’ Relay Connections

Pin Function

9 + Start Measurement Digital Input
11 - Start Measurement Digital Input
21 IDLE Contact 1
38 IDLE Contact 2
22 IN MEASUREMENT Contact 1
39 IN MEASUREMENT Contact 2
19 MEASUREMENT DONE Contact 1
18 MEASUREMENT DONE Contact 2

The MEASUREMENT DONE contact only closes for 5 seconds at
end of the measurement cycle. After that, the IDLE contact closes. The
display reading and analog output will then remain fixed until a new
measurement is requested.

Digital input range is 5 to 24 vdc to start measurement.

3.3.2.9 PIN OUT TABLE

The following table summarizes all the outputs/inputs available on
the three 50 pin D-Sub connectors on the back panel of the analyzer.

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Table 3-6: Pin out of Alarm Relay O/P (Top) 50 pin D-Sub Connector

pin # Description

1 Alarm Relay # 9, NC contact
2 Alarm Relay # 9, C contact 27
3 Alarm Relay # 9, NO contact 28
4 Alarm Relay # 10, NC contact 29
5 Alarm Relay # 10, C contact 30
6 Alarm Relay # 10, NO contact 31
7 Alarm Relay # 11, NC contact 32
8 Alarm Relay # 11, C contact 33

9 Alarm Relay # 11, NO contact 34
10 Alarm Relay # 12, NC contact 35
11 Alarm Relay # 12, C contact 36
12 Alarm Relay # 12, NO contact 37
13 Alarm Relay # 13, NC contact 38
14 Alarm Relay # 13, C contact 39
15 Alarm Relay # 13, NO contact 40
16 Alarm Relay # 14, NC contact 41
17 Alarm Relay # 14, C contact 42
18 Alarm Relay # 14, NO contact 43
19 Alarm Relay # 15, NC contact 44
20 Alarm Relay # 15, C contact 45
21 Alarm Relay # 15, NO contact 46
22 Alarm Relay # 16, NC contact 47
23 Alarm Relay # 16, C contact 48
24 Alarm Relay # 16, NO contact 49
25 Alarm Relay # 17, NC contact 50

pin # Description

AlarmRelay#17,Ccontact

26

AlarmRelay#17,NOcontact
AlarmRelay#18,NCcontact
AlarmRelay#18,Ccontact
AlarmRelay#18,NOcontact
+15VDC
AnalogGround
+15VDC
AnalogGround
+15VDC
Ch.#1,4‐20madcinput,HOT
AnalogGround
+15VDC
Ch.#2,4‐20madcinput,HOT
AnalogGround
+15VDC
Ch.#3,4‐20madcinput,HOT
AnalogGround
+15VDC
Ch.#4,4‐20madcinput,HOT
AnalogGround
Ch.#5,4‐20madcinput,HOT
Ch.#6,4‐20madcinput,HOT
+15VDC
SpareAnalogInput

Table 3-7: Pin out of Analog Signal (Middle) 50 pin D-Sub Connector

pin # Description

1 4-20 ma Out, Ch. # 3- HOT
2 4-20 ma Out, Ch. # 3- RET 27 Analog Ground
3 4-20 ma Out, Ch. # 4- HOT 28 0-1 vdc Out, Ch. # 9 - HOT
4 4-20 ma Out, Ch. # 4- RET 29 0-1 vdc Out, Ch. # 10 - HOT
5 4-20 ma Out, Ch. # 5- HOT 30 Analog Ground
6 4-20 ma Out, Ch. # 5- RET 31 O2 sensor Hot Input #2 (NI)
7 4-20 ma Out, Ch. # 6- HOT 32 O2 sensor Return Input #2 (NI)
8 4-20 ma Out, Ch. # 6- RET 33 Thermistor for O2 sensor #2 ((NI)
9 4-20 ma Out, Ch. # 7- HOT 34 Thermistor for O2 sensor #2 (NI)

pin # Description

26 0-1 vdc Out, Ch. # 8 - HOT

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GC-Pro TCD Installation

pin # Description

10 4-20 ma Out, Ch. # 7- RET 35 O2 sensor Hot Input #3 (NI)
11 4-20 ma Out, Ch. # 8- HOT 36 O2 sensor Return Input #3(NI)
12 4-20 ma Out, Ch. # 8- RET 37 Thermistor for O2 sensor #3 (NI)
13 4-20 ma Out, Ch. # 9- HOT 38 Thermistor for O2 sensor #3 (NI)
14 4-20 ma Out, Ch. # 9- RET 39 O2 sensor Hot Input #4 (NI)
15 4-20 ma Out, Ch. # 10- HOT 40 O2 sensor Return Input #4 (NI)
16 4-20 ma Out, Ch. # 10- RET 41 Thermistor for O2 sensor #4 (NI)
17 Analog Ground 42 Thermistor for O2 sensor #4 (NI)
18 Analog Ground 43 O2 sensor Hot Input #5 (NI)
19 0-1 vdc Out, Ch. # 3 - HOT 44 O2 sensor Return Input #5 (NI)
20 0-1 vdc Out, Ch. # 4 - HOT 45 Thermistor for O2 sensor #5 (NI)
21 Analog Ground 46 Thermistor for O2 sensor #5 (NI)
22 0-1 vdc Out, Ch. # 5 - HOT 47 O2 sensor Hot Input #6 (NI)
23 0-1 vdc Out, Ch. # 6 - HOT 48 O2 sensor Return Input #6 (NI)
24 Analog Ground 49 Thermistor for O2 sensor #6 (NI)
25 0-1 vdc Out, Ch. # 7 - HOT 50 Thermistor for O2 sensor #6 (NI)

pin # Description

(NI) = Not Implemented

Table 3-8: Pin out of Standard (Bottom) 50 pin D-Sub Connectors

pin # Description

1
2 27
3 + Output 4-20 ma - Channel 2 28 Alarm 1 C Contact
4 - Output 4-20 ma - Channel 2 29
5 + Output 4-20 ma – Channel 1 30
6 - Output 4-20 ma – Channel 1 31
7 - Output 0-1 v (Channel 1) 32 Exhaust Solenoid Hot
8 + Output 0-1 v (Channel 2) 33 Sample Solenoid Hot

9 + Start one shot input 34 Range 4 Contact/ not used
10 Remote Span + 35 Range 4 Contact/not used
11 - Start one shot input 36 Alarm 3 NC Contact
12 Remote Span – 37 Alarm 3 NO Contact
13 38 IDLE Contact 2 (one shot only)

14 39
15 40 Calibration Contact
16 Span Solenoid Return 41 Calibration Contact
17 Span Solenoid Hot 42 Alarm 2 NC Contact
18 DONE Contact 1 (one shot only) 43 Alarm 2 NO Contact
19 DONE Contact 2 (one shot only) 44 Alarm 2 C Contact

pin # Description

26

MEASUREMENT Contact 2 (one
shot only)

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Installation GC-ProTCD

pin # Description

20 Alarm 3 C Contact 45 Alarm 1 NC Contact
21 IDLE Contact 1 (one shot only) 46 Alarm 1 NO Contact

MEASUREMENT Contact 1 (one

22

shot only) 47
23 - Output 0-1 v (Channel 2) 48 Exhaust Solenoid Return
24 + Output 0-1 v (Channel 1) 49
25 50 Sample Solenoid Return

pin # Description

3.3.2.10 RS-232 PORT

The digital signal output is a standard RS-232 serial communications
port used to connect the analyzer to a computer, terminal, or other digital
device. It requires a standard 9-pin D connector.

Input: The input functions using RS-232 that have been implemented
to date are described in Table 3-7.

Table 3-9: Commands via RS-232 Input

Command Description
AS <enter> Auto Span immediately (continuous mode)

SV <enter> Switch to Span Valve
ZV <enter> Switch to Zero Valve
AV <enter> Switch to Analyze Valve
C1 <enter> If in 1Shot mode, start a cycle
C2 <enter> If in 1Shot mode, start a span cycle
PMA <enter> Switch to standard message
PMB <enter> Switch to TCD output mode
PMC <enter> Switch to Query Mode (used for interface with

OPC server)

Implementation: The RS-232 protocol allows some flexibility in its
implementation. Table 3-8 lists certain RS-232 values that are required
by the Standard Mode GC-Pro TCD implementation.

Table 3-10: Required RS-232 Options

Parameter Setting

Baud 9600
Byte 8 bits

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GC-Pro TCD Installation

Parity none
Stop Bits 1
Message Interval Sent at the end of each cycle.

3.3.3 Gas Connections

The analyzer gas connection diagram identifies the various gas
connection points as to function and location. Figure 3-1 shows the gas
connection points for instruments fitted with the optional auto
calibration module.

Figure 3-3: Gas Connections

Gas connections to the instrument are made at the 1/8”or 1/4”
stainless steel tube fittings provided on the rear panel. Note that the
optional purge and sensor vent fittings are 1/4” while all other gas
connections are 1/8”.

Before tubing is connected to the system, it must be decontaminated
to eliminate any hydrocarbon deposits. Using a small torch, heat each
length of tubing while passing nitrogen through it until it glows red.
Begin at the nitrogen source end and proceed down the length of the

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Installation GC-ProTCD

tube, “chasing” the red glow (and hydrocarbon deposits) down to the
open end of the tube. Cap the tubing while not in use with suitable non­contaminating caps.

All sample, calibration, and supporting gas lines, which deliver gas
to the analyzer, must be decontaminated before connection; vent lines do
not.

When connecting the various gas lines to the system, be absolutely
certain that no “dead ends” are left; that is, no unused branch lines
should be left capped off, where pockets might form of material that is
not representative of the current contents of the line, or which might
keep contaminants from being purged out of the system.

CAUTION: THE GASES USED MUST BE OF THE HIGHEST

QUALITY, ULTRA ZERO GRADES, AS SHOWN
BELOW. FAILURE TO DO SO WILL RESULT IN
CONTAMINATION AND FAILURE TO DETECT AT
THE REQUIRED ACCURACY.

Normally, two supporting gases (carrier gas and span gas) will be
required to operate the analyzer. The recommended composition for the
span gas is specified Appendix C: Addendum and Testing Results. Zero
calibration is handled electronically and does not require a separate gas
source. The support gases should be supplied from cylinders that are
equipped with an appropriate type of regulator.

CAUTION: UNDER NO CIRCUMSTANCES SHOULD YOU

EMPLOY A REGULATOR THAT IS NOT EQUIPPED
WITH A METALLIC DIAPHRAGM ANYWHERE IN THE
SYSTEM.

The regulators should be inspected prior to installation to be sure
that they are oil-free. Failure to comply with these directives will result
in a constant drift in analyzer output, as organic compounds will outgas
into the plumbing system at a rate that is related to the ambient
temperature. Use 316 stainless steel, dual-stage stainless steel diaphragm
regulators; shutoff valves should be used downstream from each
regulator.

Place the supply cylinders as close to the analyzer as possible, and
connect to the analyzer with new tubing. Be sure that all plumbing
connections are free of leaks.

Note: Use only stainless steel tubing throughout the system.

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GC-Pro TCD Installation

Consult the assembly, piping, outline drawings, and any
Addenda included with this manual to determine if special
conditions apply.

3.3.3.1 EFFLUENT

All the gases introduced into the detection cell vent from one fitting
at the rear of the analyzer. TAI recommends that the cell be permitted to
vent directly to the atmosphere wherever possible.

If optional features such as an FID detector are installed, a vent line
is required. With this option the installation must include a drop-out pot
to collect the water that is formed by the burning of the hydrogen or
other fuel.

Any vent line must be constructed so that water and dirt cannot
collect in it.

3.3.3.2 SENSOR VENT

The sensor vents through a separate vent at atmospheric pressure.
This vent may contain water and so any connection made to the port
must slope downwards for proper liquid removal. Never allow the vent
to clog or fill with liquid. It must be free-flowing and be without kinks
or obstructions.

3.3.3.3 CARRIER GAS CONNECTION

The carrier gas supply is also used as the reference gas for the TC
sensor. The specific gas used is application dependant and is listed in the
Addendum and Testing Results section of Appendix C.

The carrier gas should be supplied at 80 psig. Make the
carrier/reference gas connection according to the gas connection
diagram included at the back of this manual.

3.3.4 Sample and Span Gas Connections

The sample and span gas connections are made at the rear panel. If
the optional auto calibration module is installed, the sample and span gas
will connect to this module. If no auto calibration module is present,
these gases connect to the labeled fittings on the rear panel.

Set the supply pressure for sample and span gas to 20 psig.

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Installation GC-ProTCD

3.4 Placing the System in Operation

See Section 4 for information on starting the analyzer for the first
time. Make sure that all electrical connections have been made correctly
and all connectors are fully seated. Make sure all gas connections are
correct and leak–free.

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GC-Pro TCD Operation

Operation

This section of the manual describes how to setup and operate the
GC-Pro TCD Analyzer. It includes preliminary steps and equipment
needed for operation, initial startup, and then the actual operation of the
analyzer using the touch screen interface is described. You should read
this chapter in its entirety and become familiar with the operating
characteristics of this system before starting the analyzer for the first
time. The Addendum and Testing Results section of Appendix C lists the
software revision and default settings for your specific analyzer.

The GC-Pro TCD Analyzer r incorporates a Human/Machine
Interface (HMI) that uses a touch-sensitive LCD display with menus
logistically grouped for easy, intuitive access to all functions. The
features supported by the newly designed system HMI interface include:

1. Sensor data acquisition, data logging and system health

monitoring performed through the touch-screen display.

2. Firmware up-grades of the 89C5131 PCB can be carried out

through an internal USB 2.0 interface

3. Firmware up-grade for the 9261 controller board can be carried

out through the USB 2.0 interface using the SAMBA tool.

4. Stand alone testing of the 89C5131 PCB can be performed

through the debug hyper terminal (9600Kbps) connection on the
rear panel.

Operation of the analyzer including setup functions are performed
from the touch screen. The HOME screen is the main display screen and
the MENU screen allows the user to enter any phase of operation,
calibration, and setup simply by touching the specific on-screen button.
See Section 4.5 and following sections.

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Operation GC-Pro TCD

4.1 Equipment

The following supporting gases and hardware will be required to

operate the (standard) analyzer:

1. Carrier Gas: A cylinder of nitrogen gas, zero gas quality,

equipped with dual stage metallic diaphragm regulator is
required.

2. Span Gas: A cylinder or a permeation device system, capable of

generating known concentration of the species of interest will be
required to standardize the analyzer.

3. Sample Pressure Regulation: An oil-free, metallic diaphragm

regulator must be installed at the sample point when possible; see
Section 3.3.3 Gas Connections.

Note: Depending on the installed options other support gases

may be required. If so equipped, an addendum to this
manual will be included that describes the required gases,
hardware, setup and operational details.

CAUTION: THE GASES USED MUST BE OF THE HIGHEST

QUALITY, ULTRA ZERO GRADES, AS SHOWN
BELOW. FAILURE TO DO SO WILL RESULT IN
CONTAMINATION AND FAILURE TO DETECT AT
THE REQUIRED ACCURACY.

CARRIER GAS: NITROGEN GAS, ULTRA ZERO
GRADE WITH THC LESS THAN 0.05 PPM.

4.2 Preliminary Power-Off Check List

Make the following checks of the installation before proceeding

further into the start-up procedure:

1. Check to see that the sample and supporting gas installation is in

accordance with the specifications called for in the installation
and application sections of the manual (Chapter 3). Be sure that
the supporting gases are of the proper composition and are
connected to the correct fittings at the rear of the analyzer.

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GC-Pro TCD Operation

2. Check to see that the electrical installation conforms to the

instructions contained in the installation section (Chapter 3) and
on the input-output diagram.

3. Remove the top cover and check to see that the printed circuit

boards and cables are firmly seated in their respective sockets.

4. Confirm that recorder and alarm connections are properly made.

4.3 Powering Up the Unit

Before applying power to the analyzer for the first time perform the
following checks:

1. Make sure that the proper power 120/220 VAC 50/60 Hz is

available.

2. Connect the AC power cord to the rear panel and then plug the

other end into the mains supply. As soon as power is established,
the unit will turn on.

3. Check that the Power, CPU, and COM LEDs illuminate and the

Teledyne Logo screen appears on the display.

4. Momentarily, the Teledyne screen will be replaced with a second

start-up screen that lists the Model, Serial Number, Software
Version and other parameters specific to your instrument.

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Operation GC-Pro TCD

5. A 4-hour warm up time is required when the unit is cold. This

allows sufficient time for the internal heaters to come up to the
required temperature and stabilize. The screen will indicate a
countdown as the warm up period progresses. If the unit is
already warm, the warm up period may be 45 or 30 minutes
depending on the internal temperatures.

The warm up time can be defeated (not recommended) by
pressing the SKIP Warm Up button. In this case, the unit will
bypass the warm up period and immediately enter the diagnostic
phase as described below.

The user can check the internal temperature of the three heated
chambers by pressing Heater Status button. This will bring up a
an information screen as shown below.

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GC-Pro TCD Operation

This screen provides the actual temperatures in the respective
chambers. It is read-only, however once the unit has attained
operating temperature and concluded the initial power up
sequence, this screen can be used to alter the thermal parameters
of the system. See Section 4.5.7.

6. During the warm up period activate the support gases as

described in Section 4.4.

7. Following the warm up, the system will initiate a self-diagnostic

routine and display the results as either “OK” or “Failed”

8. After the self diagnostic test has completed the instrument will

enter the analyze mode and display the analyze screen. See
Section 4.5.13.

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4.4 Activating the Support Gases

The instrument gas controls are located on the front panel adjacent to
the touch screen display as shown in Figure 1-1. Make sure that the
following support gases are available at the analyzer:

 Carrier gas: (usually nitrogen but refer to Appendix C for

your specific application.

 Span gas: Typically 70-90% of measured component on

the range of interest in a clean background gas.
Refer to Appendix C for the specific span gas
composition for your application.

4.4.1 Carrier Gas

Set the carrier gas source regulator to 80 psig and adjust the analyzer
sample regulator until the sample pressure gauge reads the
recommended sample pressure of 7.0 psig.

4.4.2 Span Gas

1. Feed span gas to the analyzer (see Section 4.4.2). Gas switching

can be performed manually or handled through the auto
calibration valves (if the option is added). See Section 4.5.10.3.

2. Observe that the analyzer sample flow meter reads from 0.3 to

1.0 SCFH.

3. Turn off span gas.

4.5 Analyzer Operation

Although the GC-Pro TCD has been programmed for your
application at the factory, it can be further configured at the operator
level. Depending on the specifics of the application, this might include
all or a set of the following procedures:

1. Setting system parameters
 Establish a security password, if desired, requiring operator

to log in.

 Establish and start an automatic calibration cycle (if equipped

with the optional auto calibration module).

2. Routine operation.

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GC-Pro TCD Operation

 Calibrate the instrument.
 Choose auto ranging or select a fixed range of analysis.
 Set alarm setpoints and modes of alarm operation.

3. Special functions setup.
 Calibrate analog output, select analog output source, assign

names for groups and peaks, etc..

Procedures for accessing and/or changing parameters as well as
analyzer operation are detailed in the sections to follow. All functions
can be accessed from the MENU screen which is accessible via the
center button on the HOME screen.

The default screen is the HOME screen (see Section 4.5.2). This is
the analysis display and shows details regarding the current sample
being analyzed. However, the user can go directly to any function
supported by the analyzer by pressing the MENU button. The only
exception to this is when the instrument is powered up. It will go
through a warm-up period, followed by a diagnostic self-test routine as
explained in Section 4.3.

4.5.1 Default Parameters

The versatility of this analyzer usually results in significant changes
being made to parameters over the course of time to better suit a
particular application. Occasionally processes change requiring
alteration to alarms, filter settings etc. At some time, it may be
beneficial to reset the analyzer to the default conditions as it was when
shipped from the factory. Below is a listing of the default parameters
used in configuring the typical GC-Pro TCD instrument. Your specific
application may require different settings. Refer to the Addendum and
Testing Results section of Appendix C for any specific changes or
recommendations that apply to your application.

Range/Application: Refer to the Addendum and Testing

Results section of Appendix C

Range: Manual
Alarms: Defeated, 20ppb, 50ppb, HI, NON-

FAILSAFE, NON-LATCHING

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Auto Span Timing: Defeated, every 7 days, at 12 hours
Span: 80 ppb
Password: 11111

4.5.2 The HOME Screen

The HOME screen is the default display and represents the Analysis

Mode of the instrument. It is a set of two screens that present

information regarding the current measurement state. The HOME screen
is where the maximum information about the instrument is displayed.

The Group name/tag is listed on the left most column and the
concentration for groups are displayed in PPB, PPM or % depending on
the range and value. The Enabled group is represented by the glowing
LED. Each group has three user settable ranges R1, R2, and R3 and the
current range index is displayed in the Group row. It is possible to view
the VS (Volt-second) count by touching the “Vs Count” button.

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GC-Pro TCD Operation

The phase cycle (forward or reverse) and corresponding phase timer
along with the cell ADC value are displayed in the lower box. The green
LED within the rectangle starts blinking whenever a peak is detected for
active time frames (groups) running in the respective cycle.

The ten groups are split into two screens showing five on each
screen. Either screen can be displayed by selecting “NEXT” and
“PREV” on the HOME screen.

A “Cold Boot” button is located on the bottom left corner of the
HOME screen that when pressed will allow the user to revert back to
factory settings or retain the current instrument settings. See Section

4.5.13.5 for additional details regarding a cold boot.

Each group has buttons associated with it (T_Time and T-Cycle) that
will bring up a graph displaying the analysis trend in the group with
respect to time or cycle. With these buttons, the user can evaluate the
instantaneous analysis as opposed to waiting for a complete cycle to
terminate. See Section 4.5.13 for more details.

4.5.3 The MENU Screen

Instrument parameters can be accessed and set by pressing the
“MENU” button on the HOME screen. This brings up the following
MENU screen:

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Operation GC-Pro TCD

Any function can be entered by touching the respective icon. The

functions are:

 Standby (lower left corner on display)
 Home (home icon at bottom center)
 Overlay Chromatogram
 Timing
 Temperature
 Group Setup
 Analog Adjust
 Calibration
 Self Test
 Settings
 Firmware Upgrade

These functions are described in the sections that follow.

4.5.4 Standby

This function allows you to place the instrument in STANDBY

mode.

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CAUTION: STANDBY SHUTS DOWN POWER TO THE DISPLAYS

ONLY. INTERNAL CIRCUITS ARE STILL ENERGIZED
AND ELECTRICAL SHOCK HAZARD STILL EXISTS.

To place the instrument in STANDBY status press the “Standby” button
at the lower left corner of the display. The following Confirmation
screen will pop up.

Selecting ‘OK” puts the system goes into a sleep mode and
following window will be displayed on the screen.

To come out of standby mode, touch the “WAKE UP” button. An
informational pop up screen will appear for approximately one minute
displaying a message “Please wait……”.

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Operation GC-Pro TCD

4.5.5 Overlay Chromatogram

Selecting “Overlay Chromatogram” brings up the following screen:

The above screen displays the overlay chromatogram with the ADC
values on y axis plotted against the sample number on the x axis. To
display the graph onscreen, touch the “PLOT” button. To clear the
screen touch “REFRESH”.

Use the “Scale” button to change the X axis or Y axis scaling.

Note: The chromatogram will be displayed for a maximum of 1020

samples. The chromatogram will not display if the total
sum of the forward phase duration & backward phase
duration is more than 1020 seconds.

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GC-Pro TCD Operation

In this screen, low and high limits on the X and Y axes can be input.
The maximum limit for X-High is 1020 i.e., 1020 seconds. So the
maximum cycle time (forward + backward) time should not exceed
1020 seconds (17 min) for the overlay chromatogram.

The user can also select the number of channels to be plotted on the
overlay chromatogram screen by selecting the “Setting” ico n from the
MAIN menu. Doing so will display the Setting submenu screen as
shown below.

From this menu, touch the “Overlay Chro’gram” button. This will
bring up the CHANNEL SELECTION window as shown below.

Use the UP ARROW to select the number of channels then touch
ENTER to confirm the selection or CANCEL to abort the selection and

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Operation GC-Pro TCD

return the previous selection. This screen also provides the color
indicators for the plot on the various channels. These colors are fixed
and cannot be changed.

4.5.6 Timing

Timing controls the parameters of the valve and data acquisition. It
is specific to the setup of the instrument and must be determined at the
factory or TAI trained personnel. Refer to the Addendum and Testing
Results section of Appendix C for the specific timing settings used for
your system and application. Do not change these values unless directed
by Customer Service at TAI. For further information please contact TAI
Customer Service.

In the event the timing must be changed or viewed, touch the
“Timing” icon on the MENU screen. The following screen is displayed.

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GC-Pro TCD Operation

The window screen is used to set the forward and backward duration
in MM:SS format. After setting the required duration, select the ENTER
button to save the values.

If the onscreen LED is red, all available buttons will be disabled and
timing cannot be adjusted. Wait until the LED turns green again before
resuming any button presses.

Note: The chromatogram will be displayed up to a maximum of

1320 samples i.e. if the sum of the forward plus backward
phase duration is more than 1320 seconds. Beyond that
value, that the chromatogram will not be displayed.

With the LED green, the “Parameters” icon can be selected to view
and edit several parameters for each time frame, as shown in the screen
below.

The above screen displays the Phase, Begin Time and End Time
along with the active ON/OFF field. The screen also contains an EDIT
button that can be used to view or modify all the parameters for the
selected timeframe, as shown below.

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Operation GC-Pro TCD

The parameters can be modified by either touching the UP arrows or

by entering the values in input fields.

In order to input the Begin/End Time, touch on the Green “EDIT

TIME” button. This causes an input window to appear as shown below.

In this screen, the Begin/End Time can be changed (minutes and
seconds) by touching the requisite box. A pop up numerical keypad
appears onscreen that allows the direct input of numerical values.

If an inappropriate value is input, for example a Begin time greater
than the End time or an End time which exceeds the selected
(FWD+BCK) phase duration, an onscreen warning will appear as shown
below.

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Once a valid input has been entered as shown in the example screen
above, the display will return to the Parameter window, which will now
reflect the modified values.

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Operation GC-Pro TCD

After modifying the above parameters touch the ENTER button to
save the new inputs. A confirmation window will pop up before actually
saving the inputs. Select OK to save, otherwise touch CANCEL to reject
the new inputs.

4.5.6.1 TCD AMPLIFIER GAIN

The GC-Pro TCD allows separate gain adjustments on the TCD
amplifier. This affects the detector sensitivity and is most noticeable
when zeroing or making fine adjustments to the TCD detector as
described in Section 4.5.12.8. The amplifier gain can be set in the GAIN
field using a valve from 0-9 with 0 representing no gain and 9 the
maximum gain. Each component can have its own gain setting.

To set the gain, press the TIMING icon from the MAIN screen and
then press PARAMETERS. Select the component desired and then
EDIT. Enter a value from 0 to 9 in the GAIN field to set the desired gain
setting. Press ENTER and the save requester will appear which will
allow the gain setting to be changed (ENTER) or cancelled (CANCEL)
making no changes and returning the previous gain setting.

4.5.7 Temperature

Temperature control is a critical factor in GC analysis. The GC-Pro
TCD Analyzer incorporates three dedicated heaters with temperature
control PCBs.

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 Sensor
 GC Column
 Sample Chamber

Refer to the Addendum and Testing Results section of Appendix C for
the specific temperature setpoints used for your system and application. Do
not change these values unless directed by Customer Service at TAI. For
further information please contact TAI Customer Service.

Caution: The temperature settings have been carefully

determined and set at the factory for your
application. Temperature is a key factor in
determining the accuracy of the resultant
analysis. It is recommended that the user consult
TAI before making any changes to the
temperature setpoints as listed in Appendix C of
this manual.

To monitor the temperatures, check the status of a thermocouple or
change a temperature controller setpoint select “Temperature” from the
MAIN screen. The following screen will display.

4.5.7.1 THERMOCOUPLE

Selecting “Thermocouple” from the Temperature menu shows the
actual temperature reading (°C) of the three sections: Sample, Sensor,
and Column.

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The temperature sensor value will be displayed in degrees
Centigrade. If the values are within the limits the green LED will be
illuminated. The LED will be red if the values are above or below the
setpoint limits. The screen also displays the date and time of the
thermocouple data acquisition. The values are updated every five
seconds.

4.5.7.2 SETTINGS

To redefine the limits and offset for the thermocouple values, press
“Settings” from the Temperature screen. The following screen will
appear.

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Pressing any data box will bring up an onscreen numerical keyboard
that allows data input. When finished making setpoint, limit and offset
changes, press ENTER to return to the Temperature screen.

4.5.7.3 PID SETTINGS

The temperature controllers used in the GC-Pro TCD are three-term
controllers with proportional (Kp), Integral (KI), and derivative (Kd)
settings. Together, these parameters determine the overall control and
response of the instrument.

Optimum values for Kp, KI, and Kd have been determined at the
factory and set for your instrument. The PID Settings menu from the
Temperature main menu will display the current values for each of the
three heaters and allow the user to modify the setting.

To access the parameters, press PID Settings from the Temperature
screen.

Pressing PID Settings will bring up the following screen that
displays the current settings for each of the three temperature
controllers.

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Operation GC-Pro TCD

You can adjust any of the three PID constants by touching the data
box and entering a new value into the numerical entry box that pops up.
Once the value has been entered, press ENTER on the entry box to
accept the value and dismiss the numerical entry box. After all
parameters have been set, save the values by pressing ENTER on the
lower left corner of the screen. This will return you to the Temperature
main screen.

4.5.7.4 STATUS

The STATUS screen displays the status for the three thermocouple
sensors. If a thermocouple is open or damaged, this condition will be
indicated by the message “Broken” in the corresponding sensor column.
Otherwise, if a thermocouple is operating properly “Normal” will be
displayed in the sensor column.

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4.5.8 Group Setup

Group Setup assigns to each compound a name, a range given in
Range settings and an associated peak window that is determined in
Timing settings. These values should not be modified unless directed by
TAI customer Service.

When the Group Setup icon on Main Menu is selected, the following
screen is displayed.

The Group Setup is function split into two screens covering Groups
0-4 and 5-9 on individual setup screens. The Group Setup screen gives
the option to display either half of the Groups by touching the relevant
icon. When user touches the “Group 0-4” icon, a new window appears
as shown below.

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Operation GC-Pro TCD

From these screens (0-4 and 5-9) a specific group or groups can be
selected, names (tag) assigned, a range assigned as well as concentration
peaks (Sxx) added or subtracted.

A group is selected by touching the adjacent LED. When selected it
the LED icon should turn green.

A tag is limited to three characters (letters or numbers 0-9). A tag
can be assigned by touching any three keys provided in the on-screen
keypad after selecting the tag field for the relevant group. You must
press ENTER on the keypad to assign the tag before moving to another
setting or group, otherwise the tag will NOT be assigned.

To assign a range, touch the UP arrow button adjacent to the range
of the selected group.

Once all the required inputs have been made, select ENTER to save.
A confirmation window pops up to confirm the inputs or cancel.

Note: You can view the first of the Enabled Sxx on the Group

Setup screen for the respective Groups. If none of the Sxx
are enabled S** will be displayed. Details for enabling the
Sxx are given below.

It is possible to add or subtract concentration peaks to groups using
the SUM function available from the Group Select screen.

Selecting SUM from a selected group brings up an additional screen.

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This screen has three inputs for ten peaks S00 through S09. The
possible inputs are Subtract, Add, and NA (Not Applicable). The user
can assign these inputs by touching the UP arrow button available. After
touching the ENTER button to save the inputs, a confirmation window
pops up.

Note: After selecting the ENTER button there will be a delay of

few seconds to update the inputs. All other buttons (i.e.
home, cancel, back etc) available on the screen will be
disabled during the delay period.

As an example, assume Groups G00 and G01 have been setup to
monitor two different hydrocarbons with peaks associated as follows:

Group Assigned Peak

G00 S00
G01 S01

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Operation GC-Pro TCD

Then, it is possible to setup a group to monitor total hydrocarbon as
G03 which would have both hydrocarbon peaks assigned to it by using
the SUM function:

Group Assigned Peak

G00 S00
G01 S01
G02 S01 + S02

Similarly, group setup inputs can be provided for the other five
groups by selecting Group 5-9 icon on the first Group Setup screen.

4.5.9 Analog Adjust

The GC-Pro TCD Analyzer has ten 4-20 mA DC output channels
that can be assigned to the various groups. Any group can be assigned to
any output channel and it is also possible to assign groups to multiple
channels.

Channel 0 and channel 2 are unique channels. For these channels the
user can assign gain and offset values to the output. Channel 0 has an
additional feature called “WAVE” which when selected will assign the
ADC counts to the 4-20 mA output for the group assigned to channel 0.

Note: The WAVE function will not be accessible until a group has

been assigned to channel 0.

Selecting Analog Adjust from the MAIN screen brings up the
following screen.

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Pressing GROUP and assigning a specific group to Channel 0, the

screen changes to:

where WAVE function is now available.

Any group that is available (see Section 4.5.8 Group Setup) can be

assigned to any output channel.

To assign a group to a channel: (INFORMATION REQUIRED ON

HOW TO DO THIS)

4.5.10 Calibration

The SPAN function is used to calibrate the analyzer. Span can be
performed either manually or automatically with the auto calibration
function if equipped. Typically, each group will require a separate
calibration.

The analyzer is calibrated using span gas as described in Section

4.4.2. See also Appendix C Addendum and Testing Results for any
specific requirements regarding span gas for your application. This
section assumes that this gas has been properly connected and the line
checked for leaks.

To initiate a span calibration, touch the Calibration icon on the
MAIN screen. The following screen is displayed.

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4.5.10.1 SPAN

When user touches SPAN the following screen is displayed.

This screen allows the user to select which group or groups to
calibrate. There are two separate screens, one for groups 0 through 4 and
another for groups 5 through 10. Both screens function identically and
allow the user to input the concentration of the known span gas for each
group, set the concentration unit as parts per billion (ppb), parts per
million (ppm) or percent (%) and span calibrate the group or groups.

Selecting “GROUP 0-4” brings up the following screen:

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A similar screen displays if Group 5-9 is selected.

A lit green LED next to a group indicates the group is enabled
(selected) for calibration. An unlit green LED means the group has not
been selected and will not be calibrated. Touching on the group’s LED
will toggle the LED between lit (enabled) and unlit (deselected).

The SPAN value inputs for each selected group in any of the three
units PPB, PPM or Percent can be entered by touching the respective
yellow LED next to the correct unit input box. A numerical keyboard
will pop up allowing the user to input the known composition of the

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span gas. After inputting the value, press ENTER on the pop up
keyboard to input the value into the box.

Only inputs with the glowing yellow LED will be affected. When
user touches the ENTER button the inputs with the glowing yellow LED
will be saved following confirmation on the pop up screen.

To initiate the calibration, touch the “SPAN BEGIN” button and
then “OK” on the next pop up screen to calibrate the analyzer for the
selected groups.

Once calibration is complete, the display will revert to the HOME
screen. The same procedure can be followed for calibrating groups 5-9.

4.5.10.2 ALT SPAN

If a particular compound of interest is not available or not contained
in the span gas, another compound existing in the span gas can be used
for the alternate calibration. This requires assigning a factor that results
in a best fit approximation to the calibration standard normally required
for that group. These factors must be determined by the factory since
entering an incorrect value will seriously affect the measurement
capability of the instrument for that group. For this reason, TAI
recommends contacting customer service before using the Alt Span
function.

Touch the ALT SPAN listing on the Calibration screen to enter the
Alt Span function. The following screen is displayed:

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The function is split into two screens addressing to Groups 0-4 and
5-9. The screen below shows the display addressing Groups 0-4 (Group
5-9 screen is similar).

In this screen a dark green color on the LED in the “Include” column
adjacent to a group indicates that Alt Span is currently disabled for that
group. A bright green LED indicates that Alt Span is enabled for the
corresponding group. The Alt Factor value can be entered into the box in
two phases i.e., an integer part using the UP arrow on the left and a
fractional part using the UP arrow on the right.

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One the appropriate values have been entered select ENTER to save
the factor. A confirmation screen will arise asking the user to confirm
the changes before saving.

After confirmation, a display screen will appear where the user can
be the currently saved factor. If you “Cancelled” the entry on the last
screen, the previous Alt Span factor will be used.

To initiate an Alt Span calibration, touch “OK” to bring up the next
screen to select which group to span on or “CANCEL” to exit the Alt
Span function.

After pressing “OK” the next screen appears.

Use the “UP/DOWN” arrows to enter the group to span on and then
press “ENTER” to begin the calibration or “CANCEL” to exit the
function.

Once the calibration has completed the HOME screen will appear on
the display.

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Use the same procedure for performing an Alt Span on any member

or members in Groups 5-9.

4.5.10.3 AUTO CAL

The GC-Pro TCD Analyzer can be fitted with an external auto
calibration module as an option. This feature provides automatic
switching of sample and calibration gases and allows the operator to
program calibration events to occur automatically

Note: If your instrument is not fitted with an auto calibration

module, the auto calibration screens will still appear on the
display but will be non-functional.

Note: Before setting up an AUTO CALIBRATION, be sure you

understand the Span function as described in Section

4.5.10.1 and follow the procedures given there for inputting
the calibration gas compositions for each group etc. Auto
Span performs a span calibration using the target span
value set that has been set in the Span feature menu.

To setup an auto calibration cycle for a span events to occur in a
certain number of days/hours select the “Auto Cal” button from the
Calibration screen. The Auto Cal screen is displayed.

A dark green color of the LED button adjacent to the Auto Span
indicates that Auto Span is disabled while a bright green color means
that the Auto Cal feature is enabled.

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Touching the text box adjacent to either Days or Hours brings up a
numeric keypad for entering the time between calibration events (up to
255 day and/ or 24 hours). On numeric display user can see max and
min numeric value he can enter. After entering the value, press ENTER
to place the value into the onscreen box (days or hours). When the
correct values have been loaded into the Days and the Hours boxes,
touch the Green LED adjacent to Auto Cal to toggle it to the lit (bright
green) state. This enables the Auto Span feature. Or toggle it to the unlit
(dark green) state to disable auto calibration.

After pressing ENTER, a confirmation window pops up. Selecting
“OK” all inputs will be registered and the auto cal status as determined
by the state of the green LED will become active.

Touching the CANCEL button will abort the present inputs and
revert back to the last saved values and state.

Auto Cal countdown (if enabled) will begin as soon as the display
returns to the HOME screen by pressing the HOME icon.

4.5.11 Self Test

The GC-Pro TCD has a built-in self-diagnostic testing routine which
automatically runs whenever the instrument is powered up. The self­testing routine can also be run by the operator at any time by pressing
the Self-Test icon on the MAIN screen.

In the self-test routine, preprogrammed signals are sent through the
power supply, output board, preamp board and sensor circuit. The return
signal is analyzed, and at the end of the test the status of each function is
displayed on the screen as either “GOOD” or “BAD”. If any of the
functions fail, the System Alarm is tripped.

Note: The self diagnostics will interrupt analysis temporarily.

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To initiate a self-test from the MAIN screen press the Self Test icon

and then select either “Main Board” or “9261 Board”

Selecting “Main Board” displays the following screen:

After about one minute the results of the self test is displayed as
“GOOD” or “BAD” for the various tests. Once the diagnostic test has
begun, it cannot be stopped. After performing the self test the display
will revert back to the Self Test screen where you can continue the
diagnostics by selecting “9261 Board”.

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After about one minute the results of the self tests are displayed as
“GOOD” or “BAD”. The T1 to T4 tests analyze the 4 thermocouples for
continuity. Once the user enters into this screen there is no option for
stopping the self test in the middle. After performing the self test the
screen automatically reverts back to the self test screen.

4.5.12 Settings

Touching the Settings icon brings up a screen with ten functions that
are used to customize the analyzer to your specific needs plus one
information only screen. The functions available are:



INSTRUMENT INFORMATION: An information only screen
which d

isplays Manufacturer, Model, and Software version of

the instrument.

 RANGE: Used to set up three analysis ranges that can be

switched manually.

 ALARMS: Used to set the alarm setpoints and determine

whether each alarm will be active or defeated, HI or LO
acting, and failsafe or not.

 TIME: Used to set the current date and time on the

instrument.

 DETECTOR: Selects the detector used in the instrument.
 SET TCD: Allows for coarse and fine adjustments on the

TCD detector.

 PASSWORD: Used to establish password protection or

change the existing password.

 CYCLE MODE: Toggles measurement mode between

continuous measurement and single shot (measure once)
measurement and adjusts the fill time used by the sample
valve.

 OVERLAY CHROMATOGRAM: Brings up the

chromatogram display.

 COMMUNICATION: Selects between four different RS232

protocols.

CHANGE STREAM: Used to manually switch between



sample and calibration gas.

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Pressing the “Settings” icon displays the following screen:

4.5.12.1 ALARMS

The GC-Pro TCD provides two concentration alarms with relays.
When an alarm condition exists, the relay or relays will change state.
The relays are available from the 50-pin Equipment Connector as
described in Section 3.3.2.5 and 3.3.2.9. The alarms screens are used to
configure how the concentration alarms operate.

There are two identical screens within the ALARMS function, one
for setting the parameters on ALARM 1 and the other for ALARM 2.

Pressing the ALARMS button brings up a screen where you can
change or view the alarm parameters for either Alarm 1 or Alarm 2.

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Selecting ALARM 1 displays the following screen:

From this screen you can make Alarm 1 active or defeated,
configure it as a high or low alarm, failsafe or non-failsafe and whether
the alarm will be latching or non-latching by touching the respective
LED’s.

The user can enter the trigger value (alarm setpoint) by touching in
the Trigger Value box. This causes a numeric keypad to display for
entering the value. Hit ENTER to close down the keypad and enter the
value into the Trigger Value box.

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The user can also select the group to which the Alarm will be

associated by using the UP/DOWN arrows adjacent to the Source box.

The configurable items are as follows:

DEFEATED: If an alarm is defeated, its relay is de-energized,
regardless of failsafe condition. A defeated alarm does not react to a
transition over its trip point in either direction.

HIGH: If an alarm is set as HIGH, it will not create a new alarm
condition (see latching) if the analysis concentration is below the trip
point, if the analysis concentration is above the trip point, then an alarm
condition will be created or maintained.

FAILSAFE: A non-defeated alarm that is in FAILSAFE mode
energizes an alarm relay in a non-alarm condition and de-energizes an
alarm relay in an alarm condition.

Note: Failsafe condition of an alarm is a software property. This

is not related to relays that have both normally-open and
normally-closed terminals.

LATCHING: The latching property configures the alarm such that the
user must manually relieve the alarm condition even though the
concentration no longer violates the trip point of the alarm. So, if an
alarm is NON-LATCHING, and the analysis concentration temporarily
drifts above the trip point of a HIGH alarm, the alarm condition occurs
only during the time the concentration is above the trip point. If that
alarm were LATCHING, the alarm condition would persist (even though
the concentration is no longer above the trip point), until the user
released it.

RELEASING A LATCHED ALARM: When alarm conditions are
present, the relay associated with that alarm changes state. To reset from
an alarm condition, enter the Alarm 1 or Alarm 2 screen and disable the
alarm. Then re-enable the alarm. If the alarm condition s till exists, the
alarm will again trigger.

TRIGGER POINT: This is the threshold at which an active alarm can
enter into alarm condition. If an alarm is HIGH, ACTIVE, and set at

20.00 ppb, then when the analysis concentration is at or above 20.00 ppb
an alarm condition is initiated or maintained.

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CAUTION: IT IS NOT GOOD PRACTICE TO SILENCE AN

EXISTING ALARM BY SETTING THE ALARM
ATTRIBUTE TO ‘DEFEAT”. THE ALARM WILL NOT
AUTOMATICALLY RETURN TO “ACTIVE” STATUS.
IT MUST BE RESET BY THE OPERATOR. IF IT IS
NOT RESET, YOUR PROCESS WILL BE RUNNING
WITHOUT THE SAFEGUARDS THIS INSTRUMENT IS
DESIGNED TO PROVIDE.

When finished configuring the alarms, touch the ENTER button at
the bottom right corner of the screen. A confirmation window will pop
up and by selecting “OK” the new alarm configuration will be the active
settings. Then, by touching the HOME icon, all alarm 1 inputs will be
saved permanently. Touching the CANCEL button will abort the inputs
and return the previously saved values.

The ALARM 2 screen is an identical screen for configuring
ALARM 2.

Note: An alar m in 'alarm condition' is signaling that action must

be taken such as correcting the alarm or the analysis
concentration. If an active (not defeated) alarm has been
set to HIGH at 20.0 ppb, and the analysis concentration is
above that level, then the 'alarm condition' is occurring.

4.5.12.2 RANGE

There are three settable analysis ranges on the GC-Pro TCD
Analyzer. Both upper and lower bounds may be set. The value of each
limit on the currently selected range affects the corresponding upper and
lower value of the voltage and current of the analog outputs of the
analyzer as well as contact closures (if present) indicating which range is
current. The analog outputs from the 50–pin Equipment connector (see
Section 3.3.2.3 and Table 3-1) represent the proportion of the analysis
concentration to the currently selected range limit.

RANGE LIMITS: Ranges may be set for ppb, ppm, or percent
analysis however, range 3 can only be set at a value greater than range 2
and range 2 can only be set at a value greater than range 1.In addition,
the lower bound on each range must always be less than the upper
bound.

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To set the ranges select “Range” from the SETTINGS screen. The
following screen will appear:

Once the input range has been decided, press the corresponding LED
icon to turn it on. Touch the input box and a numerical keypad will
display from which you can enter the upper range limit (the lower limit
on each range is always zero). Once the value is entered, press ENTER
to dismiss the keypad and enter the value into the range box selected.

When finished, touch the ENTER button and the inputs with the glowing
yellow LED will be converted in other available units and a confirmation pop
up window will appear. Press “OK” button to proceed further.

Repeat the procedure for the other two ranges.

If the range values entered by the user does not follow the order
R3>R2>R1 then a warning will display.

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Touching the “OK” button allows the user to input the values again.
If the input values follow the order R3>R2>R1; a final confirmation
window pops up on the screen. Select OK to save or CANCEL ignore
the entered inputs.

4.5.12.3 CHANGE STREAM

The Change Stream function is used to manually select between
sample and calibration (span and zero) gases.

Note: If the analyzer is equipped with the Auto Calibration

feature, input from this screen will override the Auto
Calibration status.

To manually change the gas stream sent to the analyzer, press
Change Stream from the SETTINGS screen. The following screen will
appear:

Touch the UP arrow to toggle the display between
ANALYZE/SPAN /ZERO. Pressing UPDATE will select the displayed
stream and open the corresponding valve. Use CANCEL to abort the
selection.

The user can return to the analyze mode by pressing the HOME icon
or go back to the SETTINGS screen by touching the BACK button.

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4.5.12.4 TIME

The date and time are set from the Time screen. Select Time from

the SETTINGS screen.

Touching any of the Date and Time value boxes will bring up a
numerical keypad that allows the date and tie to be input. The time
settings entered in this screen sets the RTC which is interfaced to 9261
board on the I2C interface.

After selecting Time, the following below screen displays:

After entering each value press the “Enter” button on the keypad to
input the number and move to the next field. When all inputs have been
made, press the ENTER button on the display screen and then respond
to the confirmation display that appears.

Pressing “OK” saves the new date and time settings.

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4.5.12.5 PASSWORD

There are two functions in the GC-Pro TCD that if misused can
result in significant changes to the instrument. These are: Default
Settings from a Cold Boot (Section 4.5.13.5) and Firmware Upgrade.
These functions are therefore password protected functions.

The password is assignable by the user or the default password
“11111” can be used. The password can be any number between 1 and

99999.

To assign a new password, press “Password” from the SETTINGS
screen. The following screen will appear:

Touching the password box will display a numeric keypad allowing
the new password to be entered. Press ENTER on the keypad to dismiss
the keypad and insert the new password into the box.

Pressing the HOME icon installs the password and places the
analyzer back into the analyze mode. Pressing BACK also installs the
new password but returns the display to the SETTINGS screen.

4.5.12.6 COMMUNICATION

There are four different serial communications modes available to
the user and these are accessible from the Communications screen.

The available modes are:

 Detect Mode: Used with a laptop computer running custom

TAI software and is designed to interact with

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the chromatogram screen. (Contact TAI for
software upgrade).

 Query Mode: A specialized communication protocol that

enables interaction with the analyzer via an
OPC server.

 Profi Mode: This mode is compatible with a Teledyne

Valve Box (VB1-VB5) used in switching gas
streams to an analyzer.

 STD Mode: The standard mode outputs a text string every

two seconds that includes concentration,
range, and alarm status. If there are multiple
components (groups) being analyzed, the
output will cycle through each component in
sequence.

Press the Communications icon on the SETTINGS screen to enter

the communications function.

The user can shift between different serial modes by selecting the
“Serial Mode” from the above screen and then on the next screen using
the UP arrow button, cycle through the modes until the desired mode is
presented. Select the mode using the ENTER button.

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Selecting Serial Number from the Communications Screen produces
another screen which allows the user to input the serial number for the
analyzer which is used by the RS232 when in Profi mode to identify the
analyzer. Use the UP Arrow and then select the ENTER button next to
each channel. The following example screen has the analyzer serial
number set to 473200. The default serial is 100000.

4.5.12.7 DETECTOR

The GC-Pro TCD Analyzer can be equipped with optional detectors
at the time of purchase. These options include an FID (Flame Ionization
Detector) or SO

detector along with the standard TCD detector. If an

2

optional detector has been installed an accompanying addendum will be
included to describe the operation and maintenance required for that
detector. The DETECTOR function has been set up at the factory for

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your specific application and should not be changed from TCD unless
directed by TAI Customer Service.

4.5.12.8 SET TCD

With the detector set to TCD, the SET TCD function can be used to
adjust for drift on the TCD detector. It has both a coarse and fine
adjustment and displays the current ADC count received from the
detector.

To make adjustments, press SET TCD from the SETTINGS screen.
The following screen appears:

For proper operation, the ADC value should be in the range of 0 to
+10,000 counts, preferably, it should be as close to zero as possible. The
user can adjust the detector using the coarse and fine adjustment
onscreen sliders. After making an adjustment, allow the ADC value to
settle before making another adjustment. Often, just a coarse adjustment
is adequate, however the value can be fine tuned using the Fine
adjustment slider.

The amount of change associated with a FINE adjustment is often
very slight and depends on the gain value that is set in the TIMING/
PARAMETERS/EDIT screen. See Section 4.5.6.1. The TCD amplifier
in the GC-Pro TCD has 10 settings that control the gain of this
amplifier. Setting a higher gain value will produce a correspondingly
larger change when moving the FINE adjustment slider.

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4.5.12.9 CYCLE MODE

The detection cycle can be set for either a continuous measurement
cycle or for a single-shot measurement from the CYCLE MODE screen.
Although set at the factory for your application, the time allotment for
filling the sample chamber in the sample valve can also be set or
adjusted with this function.

From the SETTINGS menu, press CYCLE MODE. The following
screen appears:

Use the arrow in the Cycle Mode Selection field to toggle between
CONTINUOUS and MEASURE ONCE options. Then, if required, you
can alter the sample chamber charging time by entering appropriate
values in the FILL DURATION field.

Note: This has been set at the factory for your application and

should not require alteration. Contact TAI Customer
Service before making any changes to this parameter.

As with the other screens, you have the option of cancelling the entry
without saving changes using the CANCEL button and/or returning to
the previous screen with the BACK button.

4.5.13 Analysis Mode

Analysis mode is the default mode of the instrument where
measurements are updated after each cycle (forward + reverse) and
displayed on the HOME screen.

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The GC-Pro TCD is analyzing in both the forward and reverse
cycles and measurement value integrated over the last complete cycle is
shown in the display box adjacent to the group identifier (G00-G09,
Bnz, etc.) for any group that has been activated (LED lit). See Group
Setup for activating a group. The cycle direction and time into the cycle
are shown in the lower box as is the current ADC output value. The
current analysis range is indicated next to the Group LED.

4.5.13.1 T-TIME

Each group has “T_Time” and “T-Cycle” selectable buttons
associated with it that will bring up a graph displaying the analysis trend

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Operation GC-Pro TCD

in the group with respect to time or cycle. With these buttons, the user
can evaluate the instantaneous analysis as opposed to waiting for a
complete cycle to terminate.

The T_Trend screen shows the analysis trend with respect to time.

This screen displays the concentration behavior or trend for the

group on y axis against the time into the cycle on the x axis.

Low and High values can be set for the y axis using the “L” and “H”
boxes below the graph. Touching the “Update” button will reformat the
y axis index with the new input.

It is possible to view the instantaneous value by touching the trend
graph at the location of interest and the corresponding value will be
displayed in “Watch Line” box at the top right corner.

Note: The LOW and HIGH values must be updated by the user

as soon as system is powered on.

Note: The trend graph will not be plotted continuously; it needs to

be refreshed manually. To refresh the trend screen, press
the HOME button to return to the HOME screen and then
re-enter the trend screen by pressing trend button.

4.5.13.2 T_CYCLE

Similar to the above function, the T_Cycle button displays a graph of
group concentration versus cycles.

The T_Cycle is display is shown below.

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Both X-axis (number of cycles) and y-axis (concentration) can be
changed by touching the “Setting” button. The maximum number of
cycles that can be plotted is 300.

4.5.13.3 CHROMATOGRAM

The Chromatogram function is available from the HOME screen
using the “Chromatogram” button on the lower right corner of the
screen. This function displays the ADC count as a function of the
number of samples taken (seconds). It is useful for troubleshooting as
well as setting up new applications.

Selecting “Chromatogram” from the HOME screen brings up the
following screen:

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Touching the “PLOT” button will display the graph on the screen
and touching the “Refresh” button will clear it. Low and high limits on
both the X and Y axis can be changed by touching the “Setting” button.
This will cause the following screen to appear:

Note: The Chromatogram will be displayed for maximum 1020

samples. The chromatogram will not be displayed if the
total sum of the forward and backward phase duration is
greater than 1020 seconds.

Note: User can view the Y axis value in digital format by entering

the corresponding X axis value in the field provided with X=
symbol.

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Values for the X and Y axis are entered by touching the input box. A
numerical keypad appears that allows for numeric entry. Press ENTER on
the keypad to enter the value into the appropriate box and dismiss the
keypad. Repeat for each input box requiring an entry or change. Upon final
entry, press Chromatogram button to return to the Chromatogram screen.
The new X-axis and Y-axis values will be displayed on the screen. The
limit for X-High is 1020 i.e., 1020 seconds. So the m aximum cycle time
which is the sum of the Forward and Backw ard phase du ration should not
exceed 1020 seconds (17 min) for the chromatogram.

4.5.13.4 VS COUNT

The VS (Volt-seconds) count is a measure of the conditioned signal
coming from the detector. It corresponds to the strength of the output
signal from the detector. The VS measure is a relative value and has no
absolute relationship to concentration between groups.

4.5.13.5 COLD BOOT

The “Cold Boot” button on the HOME screen provides the user with
the option of resuming the system with user configured settings or
restoring the analyzer back to the default factory settings for all
parameters.

The Cold Boot function is a password protected function. The
default password is ‘11111’. If the password has been changed (see
Section 4.5.12.5) then the new password must be entered to gain entry
into the function that allows a change from the current setting.

Pressing “Cold Boot” from the HOME screen brings up the
following screen:

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Selecting “Current Setting” causes the analyzer to use all the
functions and settings that are presently in force, i.e. no change to the
presently saved system configuration. A confirmation window pops up
whereby selecting ‘OK” causes the instrument to start up as normal with
the present configuration. Pressing “Cancel” reverts the display to the
previous screen with no change.

However, if Factory Settings is selected, a Password Entry screen
will display requiring the user to input the system password (Default
Password is “11111”). After the password is input an “Access Check”
pop up window will display requiring the Password to be re-entered.
Press “OK” when done.

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