Thermo Scientific Nicolet FT-IR User manual

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269-159402, Rev A

Contents
Introduction........................................................................................ 1
Questions and concerns ............................................................... 2
Conventions used in this manual................................................. 2
Safety precautions........................................................................ 3
TGA-IR Module components...................................................... 4
The front panel....................................................................... 5
The rear panel ........................................................................ 7
Using the TGA-IR Module................................................................ 9
Principles of operation................................................................. 9
Setting up the module ................................................................ 10
Connecting the purge line.................................................... 10
Connecting the transfer and exhaust gas lines..................... 12
Verifying the installation..................................................... 15
Setting the temperature........................................................ 16
Using the remote start option............................................... 16
Cooling the detector................................................................... 17
Operating tips............................................................................. 19
Maintenance..................................................................................... 21
Checking and replacing fuses .................................................... 22
Troubleshooting......................................................................... 26
Specifications............................................................................. 27

TGA-IR Module User’s Guide 1
Introduction
This manual explains the features and components of the Thermo
Scientific TGA-IR Module. For information on performing TGA-IR
experiments, see the OMNIC Series Help.
Before operating the TGA-IR Module, you should have a working
knowledge of Thermo Scientific OMNIC™Series software. You will
also need to know the fundamentals of thermogravimetric analysis
and the operating characteristics of your thermogravimetric analyzer.
Warning The Accessory Safety Guide that came with your system contains
important safety information. Make sure you read this guide, and
follow the safety precautions provided there and later in this chapter
whenever you use the TGA-IR Module. 

Questions
and concerns
In case of emergency, follow the procedures established by your
facility. If you have questions or concerns about safety or need
assistance with operation, repairs or replacement parts, you can
contact our sales or service representative in your area or use the
information at the beginning of this document to contact us.
Conventions
used in this manual
This manual includes safety precautions and other important
information presented in the following format:
Note Notes contain helpful supplementary information. 
Important Follow instructions labeled “Important” to avoid damaging the
system hardware or losing data. 
Caution Indicates a potentially hazardous situation which, if not avoided,
may result in minor or moderate injury. It may also be used to alert
against unsafe practices. 
Warning Indicates a potentially hazardous situation which, if not avoided,
could result in death or serious injury. 
Danger Indicates an imminently hazardous situation which, if not avoided,
will result in death or serious injury. 
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Safety precautions Before you use the TGA-IR Module, make sure you read the
following safety precautions and both the Spectrometer Safety Guide
and the Accessory Safety Guide that came with your system. To help
prevent personal injury or equipment damage, follow all safety
precautions whenever you use the TGA-IR Module.
Warning The gas cell and the transfer line reach very high temperatures when
in use. To help avoid a severe burn or fire hazard, do not allow any
flammable object or part of the body to come into contact with the
gas cell or transfer line when they are in use. Use particular care
when working around surfaces marked with the following symbol:
Surfaces that are marked with this symbol range in temperature from
35 °C (95 °F) to 200 °C (400 °F) and can cause burns.
Warning To avoid a shock and fire hazard, do not allow water or other liquids
to come into contact with the internal components, and never attempt
to access the internal components of the TGA-IR Module. 
TGA-IR Module User’s Guide 3

TGA-IR
Module components
The TGA-IR Module and its internal components are shown in the
following illustrations.
Gas cell
Transfer line
Mirror
Mirror
Exhaust
gas line
Detector
Mirror
Electronics box
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The front panel The four indicator lights on the front panel of the TGA-IR Module
show the current status of the system.
TGA-IR Module User’s Guide 5

The table below describes the function of each indicator light on the
front panel:
Indicator Function
Power This indicator is lit whenever the module power
is on. The power switch is on the rear panel.
(See the illustration in the next section.)
Transfer Line This indicator is lit when the transfer line is
being heated. When the temperature of the
transfer line is close to the setpoint, the indicator
cycles on and off.
Cell This indicator is lit when the gas cell is being
heated. When the temperature of the cell is close
to the setpoint, the indicator cycles on and off.
Alarm This indicator is lit when an alarm condition
occurs. The system responds by shutting off the
heater power. Alarm conditions can be caused by
an open thermocouple, the temperature of the gas
cell or transfer line being too high, or a
malfunctioning heater. If an alarm condition
occurs, turn the module power off and then
contact Technical Support for assistance.
Warning To avoid burn hazard, turn off the module power whenever the
alarm indicator lights. Allow the transfer lines and gas cell to cool
before you turn on the power to the module again. 
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The rear panel The following table and illustrations describe the components on the
rear panel of the TGA-IR Module.
StartAccessory Purge in
Power
switch
AC power
connector Fuses
This component… Does this…
Purge In Connects the purge gas supply.
Start Connects a remote start cable from the
TGA.
Accessory Connects the cable from an Accessory
connector on the spectrometer.
Fuses Holds the fuses for the module.
AC power connector Connects the AC power cord.
Power switch Turns the module power on or off.
TGA-IR Module User’s Guide 7

Warning The Module is preset at the factory to connect to a particular AC line
voltage range. As shown below, the “Factory Set” label on the rear
panel indicates the factory setting. To avoid shock and fire hazard,
do not attempt to change the setting. Contact Technical Support if
your system does not meet your local power standards. 
8 Thermo Fisher Scientific

Using the TGA-IR Module
This chapter provides information about:
•Principles of operation for the TGA-IR Module.
•Setting up the module.
•Cooling the detector.
•Checking the performance of the TGA-IR Module.
•Tips for operating the TGA-IR Module.
Note Maintenance and service information for the gas cell is provided in
the TGA-IR Module Gas Cell Service Guide that came with your
TGA-IR Module. 
Principles
of operation
Thermogravimetric analysis (TGA) measures a sample’s weight
change in a controlled atmosphere as a function of temperature or
time. The change in weight occurs as the sample decomposes or
evaporates and is usually accompanied by evolved gases.
Combining a TGA and the TGA-IR Module with a Thermo
Scientific FT-IR spectrometer provides a simple and accurate
technique for identifying the evolved gases from a TGA experiment.
This provides information on sample characteristics such as thermal
stability or decomposition pathways.
The sample is loaded onto the balance of the TGA, which is
connected to the TGA-IR Module. A furnace heats the sample at a
programmed rate from room temperature to temperatures in excess
of 1000°C. The software plots a weight loss curve of the data file as
a function of temperature or time.
TGA-IR Module User’s Guide 9

A carrier gas continuously sweeps evolved gases from the furnace
tube chamber. The carrier gas may be inert, such as nitrogen, or
oxidative, such as air. As the compounds in the sample vaporize, the
carrier gas carries them through a heated transfer line and flow cell.
Here the gases are scanned by the infrared beam and the spectral
data is recorded. The gases exit the flow cell through the outlet tube
and should be vented to a fume hood or trap.
The TGA-IR Module is intended for use at ambient pressure, with
low pressure (5 psi or less) carrier gases flowing at a rate of
150 ml/minute or less. An aspirator is recommended to draw out the
exhaust gases. If you use and aspirator, set it for 10 inches Hg or
less. Operating outside these parameters could expose you to burn
hazards when heated gases vent unexpectedly.
Setting up the module After your TGA-IR Module has been installed by one of our service
representatives, you should perform the following procedures to set
up the module to collect data:
•Connect the purge line.
•Connect the transfer and exhaust gas lines.
•Set the temperature.
Connecting the purge line If you are going to purge your TGA-IR Module, read the notes and
warnings below, and then use the procedure that follows to connect
the purge line (if it is not already connected).
Note You should use the same purge gas that you use for your
spectrometer. We recommend using dry air supplied by a purge gas
generator (or pure air generator) or nitrogen. 
Note For more information about setting up the purge system and
controls, see the on-line Spectrometer Help Topics available through
the Help menu in OMNIC. Find “purge” in the index and make a
selection from the list of topics for that entry. 
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Note You should leave the purge on at all times. This keeps the module
free of undesirable gases, protects the optics and improves the
system’s thermal stability. 
Important Do not purge with argon. Purging with argon will cause the laser to
fail. 
Important To prevent the cell from becoming contaminated, do not turn on the
cell or transfer line heaters unless purge gas is flowing through
them. 
Warning Never use a flammable gas to purge the TGA-IR Module. The purge
gas must be free of moisture, oil, carbon dioxide and other reactive
or infrared-absorbing materials. 
To connect the purge line:
1. Prepare a purge line and connect it to the purge connector on
the rear panel of the module.
For more information about rear panel connectors, see “Rear
panel” in the “Introduction” chapter.
2. Adjust the purge gas supply pressure and flow rate to match
the pressure and flow rate used to purge the spectrometer.
Typically this is between 20 and 40 psi and 25 scfh. Use a
flowmeter to measure the purge flow rate.
3. Adjust the temperature.
See “Setting the temperature” in this chapter for information
about adjusting the temperature. A temperature of 220°C is
adequate for most TGA-IR applications.
TGA-IR Module User’s Guide 11

Connecting
the transfer and
exhaust gas lines
In a TGA-IR experiment, the sample gases from the TGA furnace
are conducted into the gas cell through the transfer line. The exhaust
gases produced during this process can be hazardous and should be
vented through the exhaust gas line. To connect the transfer and
exhaust gas lines, read the warnings below, and then use the
procedure that follows.
Warning If the TGA furnace or gas cell has been heated recently, make sure
you allow at least two hours for all components of the module to
cool to a safe temperature before you begin this procedure. 
Caution Make sure the power is turned off to both the gas cell and the TGA
furnace before you begin this procedure. 
Warning The TGA-IR Module is intended for use at ambient pressure, with
low pressure (5 psi or less) carrier gases flowing at a rate of
150 ml/minute or less. An aspirator is recommended to draw out the
exhaust gases. If you use and aspirator, set it for 10 inches Hg or
less. Operating outside these parameters could expose you to burn
hazards when heated gases vent unexpectedly. 
To connect the transfer and exhaust gas lines:
1. Turn off the power to both the TGA-IR Module and the
TGA furnace.
2. Connect the transfer line to the TGA furnace.
For more information, refer to the manufacturer’s documentation
that came with your furnace.
12 Thermo Fisher Scientific

3. Connect the transfer line to the gas cell transfer line
connector.
Gently push the Swagelok®fitting on the transfer line into the
gas cell transfer line connector. Turn the Swagelok fitting until
tight to secure the connection.
Transfer line
from TGA furnac
e
Gas cell transfer
line connector
TGA-IR Module User’s Guide 13

4. Connect the exhaust gas line to the gas cell exhaust gas
connector.
Gently push the Swagelok®fitting on the exhaust gas line into
the gas cell exhaust gas connector. Turn the Swagelok fitting
until tight to secure the connection.
Gas cell exhaust
gas connector
Exhaust gas line
to venting syste
m
5. Connect the exhaust gas line to a venting system.
Connect the exhaust gas line to a vent hood or whatever venting
system your facility uses. We also recommend using an aspirator
to draw out the exhaust gases. If you use and aspirator, set it for
10 inches Hg or less.
14 Thermo Fisher Scientific

6. Adjust the transfer line flow rate.
The TGA-IR Module is intended for use at ambient pressure,
with low pressure (5 psi or less) carrier gases flowing at a rate of
150 ml/minute or less. For information about adjusting the
transfer line flow rates, refer to the manufacturer’s
documentation that came with your furnace.
Verifying the installation After you have connected the purge, transfer, and exhaust gas lines,
you should verify that the installation of your TGA-IR Module was
successful. To do so, choose Experiment Setup from the Collect
menu in OMNIC™, and click the Bench tab in the Experiment Setup
dialog box. Set the Gain parameter to 2, and if you have a TGS
detector, you must set the Velocity parameter to .6329.
Once the parameters are set, look at the interferogram shown in the
live display. The voltage of at least one of the peaks (positive or
negative) should be greater than 5 volts as shown below. If neither
peak is greater than 5 volts, contact Technical Support for assistance.
TGA-IR Module User’s Guide 15

Setting the temperature To set the temperature of the TGA-IR Module, use the OMNIC
Series software. For more information, please refer to the on-line
OMNIC Series Help available through the Series menu in OMNIC.
Find “heaters” in the index and go to the “Heaters parameters” topic.
Note The cell and transfer line are heated to help prevent the condensation
of materials in the gas stream from the TGA furnace, but you should
set the temperature as low as possible for your samples. (Higher
temperatures reduce the optical throughput for the cell.) 
Note Optical throughput for the cell can also be affected by residue on the
cell windows, so you should set the cell temperature 5 to 10 degrees
higher than the temperature of the transfer line to help reduce
condensation on these windows. 
Using the
remote start option
The TGA-IR Module has a remote start option that allows you to use
your TGA furnace to start a data collection. This requires a remote
start cable, which is included with the TGA-IR Module. This cable
has a 9-pin D connector on one end and two bare wires on the other.
These wires connect to pin 7 (ground) and pin 4 (start collection) on
the D connector and are labeled accordingly.
To use the remote start option:
1. Connect the D connector on the remote start cable to the FID
connector on the rear panel of the TGA-IR Module.
For information about the Start connector, see “The rear panel”
in the “Introduction” chapter.
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