TA Instruments TGA 2050 Operator's Manual

Thermal Analysis & Rheology
TGA 2050
Thermogravimetric Analyzer
Operator’s Manual
PN 925603.001 Rev. D (Text and Binder)
PN 925603.002 Rev. D (Text Only)
Issued July 2000
TA INSTRUMENTS TGA 2050
I
©1995, 1996, 1997, 2000
by TA Instruments, Inc.
109 Lukens Drive
New Castle, DE 19720
Notice
The material contained in this manual is believed adequate for the intended use of this
instrument. If the instrument or procedures are
used for purposes other than those specified
herein, confirmation of their suitability must be
obtained from TA Instruments. Otherwise, TA
Instruments does not guarantee any results and
assumes no obligation or liability. This publication is not a license to operate under or a
recommendation to infringe upon any process
patents.
TA Instruments Operating Software and Module, Data Analysis, and Utility Software and
their associated manuals are proprietary and
copyrighted by TA Instruments, Inc. Purchasers are granted a nonexclusive, nontransferable
license to use these software programs on the
module and controller with which they were
purchased. These programs may not be duplicated by the purchaser without the prior
written consent of TA Instruments. Each
licensed program shall remain the exclusive
property of TA Instruments, and no rights or
licenses are granted to the purchaser other than
as specified above.
II
TA INSTRUMENTS TGA 2050
Table of Contents
Notes, Cautions, and Warnings ............... viii
Hotlines ........................................................ ix
Safety ............................................................. x
Using This Manual ..................................... xii
CHAPTER 1: Introducing the 2050 ........ 1-1
Introduction................................................ 1-3
Components ............................................... 1-4
The 2050 Instrument ................................... 1-6
Automatic Keypad Functions .............. 1-9
Front Panel lights ................................. 1-9
Accessories .............................................. 1-10
Gas Switching Accessory ................. 1-10
Other Accessories ............................. 1-10
Specifications ........................................... 1-11
CHAPTER 2: Installing the 2050 ............ 2-1
Unpacking/Repacking the 2050 .................. 2-3
Unpacking the 2050 ............................. 2-3
Repacking the 2050 .............................. 2-6
Installing the Instrument ............................ 2-7
TA INSTRUMENTS TGA 2050
III
Table of Contents
(continued)
Inspecting the System.......................... 2-8
Choosing a Location ........................... 2-9
Filling the Heat Exchanger................ 2-10
Connecting Cables and Lines ............ 2-12
Heat Exchanger Cable
and Water Lines .......................... 2-12
GPIB Cable ................................. 2-14
Purge Lines ................................. 2-17
Cooling Gas Line ........................ 2-19
Power Cable ................................ 2-20
Unpacking the Balance ............................ 2-21
Installing the Hang-Down Wires....... 2-23
Aligning the Sample
Hang-Down Wire .............................. 2-27
Adjusting the Sample Platform ......... 2-31
Starting the 2050 ....................................... 2-32
Shutting Down the Instrument .................. 2-33
CHAPTER 3: Running
Experiments............................................... 3-1
Overview .................................................... 3-3
Before You Begin ............................... 3-4
Calibrating the TGA ................................... 3-5
IV
TA INSTRUMENTS TGA 2050
Table of Contents
(continued)
Temperature Calibration ....................... 3-5
Weight Calibration ................................ 3-6
Running a TGA Experiment ....................... 3-6
Experimental Procedure ....................... 3-6
Preparing the Sample .......................... 3-7
Selecting Sample
and Tare Pans ................................ 3-7
Taring the Sample Pan ................... 3-8
Automatic Tare ....................... 3-9
Manual Tare ............................ 3-9
Loading the Sample ............................ 3-10
Setting Up an Experiment .................. 3-14
Setting Up Accessories ..................... 3-15
Using a Purge Gas ....................... 3-15
Using the Air Cool Option .......... 3-18
Using the Gas Switching
Accessory .................................... 3-18
Starting an Experiment ....................... 3-20
Stopping an Experiment ..................... 3-21
Unloading the Sample ................. 3-22
Use in an Oxygen-Free Atmosphere ......... 3-23
TA INSTRUMENTS TGA 2050
V
Table of Contents
(continued)
Purge Gas System............................... 3-23
Instrument Setup ................................ 3-24
CHAPTER 4: Technical Reference......... 4-1
Description of the TGA 2050 .................... 4-3
Components.......................................... 4-5
Balance .......................................... 4-6
Sample Loading Assembly ............ 4-8
Furnace .......................................... 4-9
Cabinet ......................................... 4-11
Heat Exchanger............................ 4-13
Theory of Operation ................................. 4-14
Status Codes ............................................ 4-15
CHAPTER 5: Maintenance
and Diagnostics ......................................... 5-1
Overview ..................................................... 5-3
Routine Maintenance .................................. 5-4
Inspection ............................................. 5-4
Cleaning the Instrument Keypad .......... 5-4
Cleaning the Quartz
Furnace Tube........................................ 5-4
VI
TA INSTRUMENTS TGA 2050
Table of Contents
(continued)
Heat Exchanger ....................................5-7
Maintaining Heat
Exchanger Coolant ........................5-7
Draining and Refilling the
Water Reservoir .............................5-7
Replacing the Thermocouple ....................5-10
Diagnosing Power Problems .....................5-12
Fuses ...................................................5-12
Power Failures .................................... 5-13
TGA 2050 Test Functions ........................5-14
The Confidence Test ..........................5-14
Replacement Parts .................................... 5-16
Appendix A: Ordering Information ..... A-1
Address List ............................................... A-1
Index............................................................ I-1
TA INSTRUMENTS TGA 2050
VII
Notes, Cautions,
and Warnings
This manual uses NOTES, CAUTIONS, and
WARNINGS to emphasize important and
critical instructions.
NOTE:
A NOTE highlights important information about
equipment or procedures.
t CAUTION:
A CAUTION emphasizes a procedure that may
damage equipment or cause loss of data if not
followed correctly.
!WARNING
A WARNING indicates a procedure that
may be hazardous to the operator or to the
environment if not followed correctly.
VIII
TA INSTRUMENTS TGA 2050
Hotlines
To TA Instruments Thermal Analysis
For Technical Assistance ........ (302) 427-4070
To Order Instruments and
Supplies .................................. (302) 427-4040
For Service Inquiries............... (302) 427-4050
General Information ................ (302) 427-4000
TA INSTRUMENTS TGA 2050
IX
Safety
Electrical Safety
You must unplug the instrument before doing
any maintenance or repair work; voltages
exceeding 110 volts AC are present in this
system.
!WARNING
High voltages are present in this instrument. If you are not trained in electrical
procedures, do not remove the cabinet
covers unless specifically instructed to do
so in the manual. Maintenance and repair
of internal parts must be performed only by
TA Instruments or other qualified service
personnel.
!WARNING
After transport or storage in humid conditions, this equipment could fail to meet all
the safety requirements. Refer to the
NOTE on page 2-10 for the method used to
dry out the equipment before use.
Chemical Safety
Use only the purge gases listed in Table 1.2 in
Chapter 1. Use of other gases could cause
damage to the instrument or injury to the
operator.
X
!WARNING
Do not use hydrogen or any other explosive
gas in the TGA 2050 furnace.
!WARNING
If you are using samples that may emit
harmful gases, vent the gases by placing
the instrument near an exhaust.
TA INSTRUMENTS TGA 2050
Safety
(continued)
!WARNING
If you are routinely evaluating materials in the
TGA that lose a large amount of volatile
hydrocarbons ( e.g., lubricating oils), you need
to clean the furnace more frequently to
prevent dangerous buildup of debris in the
furnace. This is particularly important if
oxygen is used as a purge gas in the TGA
2050. See Chapter 5 for instructions.
!WARNING
The TGA 2050 furnace assembly also
contains refractory ceramic fiber (RCF)
insulation. This insulation is enclosed
within the furnace housing. The furnace
housing should only be disassembled for
replacement of EGA furnace sample tube or
furnace assemblies. Refer to instructions
provided with the sample tube or furnace
replacement kits for procedures for handling RCF insulation.
Thermal Safety
After running an experiment, allow the open
furnace and thermocouple to cool down before
you touch them.
!WARNING
During a sample run, the furnace base can
be hot enough to burn skin. Avoid contact
with the furnace base during experiments.
Mechanical Safety
!WARNING
TA INSTRUMENTS TGA 2050
Keep your fingers and all other objects out
of the path of the furnace when it is moving. The furnace seal is very tight.
XI
Using This Manual
XII
Chapter 1
Describes your TGA 2050
instrument and its
specifications.
Chapter 2
Describes how to connect
the TGA to the rest of
your system and how to
install the system.
Chapter 3
Describes how to run
TGA experiments.
Chapter 4
Provides technical
information on the
procedures described in
Chapter 5 and explains
principles of TGA operation.
Chapter 5
Describes how to perform
routine maintenance,
replace the thermocouple,
remove and reinstall the
furnace, and diagnose
power problems; also
provides an explanation
of the confidence test.
Appendix A
Lists TA Instruments
offices that you can
contact to place orders,
receive technical assistance, and request service.
Index
Lists the page numbers of
important topics for your
reference.
TA INSTRUMENTS TGA 2050
CHAPTER 1: Introducing the
TGA 2050
Introduction............................................. 1-3
Components ............................................ 1-4
The 2050 Instrument ................................ 1-6
Automatic Keypad Functions ............ 1-9
Front Panel lights .............................. 1-9
Accessories ........................................... 1-10
Gas Switching Accessory ............... 1-10
Other Accessories .......................... 1-10
Specifications ........................................ 1-11
TA INSTRUMENTS TGA 2050
1–1
Introducing the TGA 2050
1–2
TA INSTRUMENTS TGA 2050
Introduction
Introduction
Your TA Instruments Thermogravimetric
Analyzer (TGA) 2050 is a thermal weightchange analysis instrument that can be used with
any of the TA Instruments PC-based controllers.
The TGA 2050 measures the amount and rate of
weight change in a material, either as a function
of increasing temperature, or isothermally as a
function of time, in a controlled atmosphere. It
can be used to characterize any material that
exhibits a weight change and to detect phase
changes due to decomposition, oxidation,or
dehydration. This information helps the scientist or engineer identify the percent weight
change and correlate chemical structure, processing, and end-use performance.
Your controller is a computer that performs the
following functions:
•
•
•
•
Provides an interface between you and
the analysis instruments
Enables you to set up experiments and
enter constants
Stores experimental data
Runs data analysis programs.
The TGA 2050 executes thermal experiments
that have been set up on the controller. See
Figure 1.1 on the next page for an illustration of
a TGA system.
TA INSTRUMENTS TGA 2050
1–3
Introducing the TGA 2050
Figure 1.1
Thermogravimetric
Analyzer (TGA) 2050 with
PC-Based TA Instruments
Thermal Analyzer
Components
The TGA 2050 has five major components,
illustrated in Figure 1.2:
1–4
•
The balance, which provides precise
measurement of sample weight. The
balance is the key to the TGA system.
•
The sample platform, which loads and
unloads the sample to and from the
balance.
•
The furnace, which controls the sample
atmosphere and temperature.
•
The cabinet, where the system
electronics and mechanics are housed.
•
The heat exchanger, which dissipates
heat from the furnace.
TA INSTRUMENTS TGA 2050
Introduction
Balance
Cabinet
Furnace
Heat Exchanger
Sample
Loading
Assembly
Figure 1.2
TGA 2050
Components
TA INSTRUMENTS TGA 2050
1–5
Introducing the TGA 2050
The 2050 Instrument
The instrument keypad (Figure 1.3) contains
keys that control local operations at the instrument (automatic balance tare, furnace elevator,
sample loading platform, and experiment start
and stop functions).
Start
Stop
Figure 1.3
TGA 2050 Keypad
Table 1.1 explains the functions of the instrument keys.
NOTE:
1–6
Experiment information and instrument constants
are entered from the controller keyboard, not the
instrument keypad.
TA INSTRUMENTS TGA 2050
The 2050 Instrument
Table 1.1
Instrument Keypad
Function Keys
Key/Function
Explanation
TARE
Zeros the weight of an
empty sample pan:
automatically loads the
pan from the sample
platform, raises the
furnace to protect the pan
from air currents, weighs
the pan, stores the weight
as an offset, and then
unloads the pan.
LOAD
Loads a sample pan from
the sample platform onto
the balance.
UNLOAD
Unloads the sample pan
from the balance onto the
sample platform.
FURNACE
Toggles between the
furnace closed (up) and
furnace open (down)
functions, depending on
where the furnace is when
you press the key. This
key can be pressed while
the furnace is moving to
reverse the direction of
movement.
START
Begins the experiment.
This is the same function
as Start on the controller.
(table continued)
TA INSTRUMENTS TGA 2050
1–7
Introducing the TGA 2050
Table 1.1
Instrument Keypad
Function Keys
(continued)
Key/Function
Explanation
STOP
If an experiment is
running, this key ends the
method normally, as
though it had run to
completion; i.e., the
method-end conditions go
into effect, and the data
that has been generated is
saved. This is the same
function as Stop on the
controller.
If an experiment is not
running (the instrument is
in a stand-by or methodend state), the STOP key
will halt any activity (air
cool, all mechanical
motion, etc.).
1–8
TA INSTRUMENTS TGA 2050
The 2050 Instrument
Automatic Keypad
Functions
Some of the TGA instrument keys automatically
perform additional functions under certain
conditions:
•
START automatically loads the sample
pan and closes the furnace, if necessary,
before beginning the experiment.
•
TARE, LOAD, and UNLOAD
automatically open the furnace if
necessary.
•
START can be pressed while a sample
load is in progress.
Front Panel
Lights
The front panel green power light shows that the
instrument is on; the yellow light shows that the
instrument is ready.
TA INSTRUMENTS TGA 2050
1–9
Introducing the TGA 2050
Accessories
Gas Switching
Accessory
The TA Instruments Gas Switching Accessory
can be used to turn the purge gas on and off or to
switch between two different purge gases during
TGA experiments.
Other Accessories
The TGA can be used with many standard
analytical accessories offered by various manufacturers, including vacuum, FTIR, gas chromatographs, mass spectrometers, and evolved
gas analyzers. Consult the appropriate local
instrument manufacturer for further information.
1–10
TA INSTRUMENTS TGA 2050
Specifications
Specifications
Table 1.2
TGA 2050
Specifications
Temperature range
25oC to 1000 oC
Thermocouple
Platinel II*
Heating rate
0.1 to 50°C/min
Operating line voltage
115 volts,
50/60 Hz
1.5 kVA
Energy consumption
*Platinel II is a registered trademark of
Engelhard Industries.
TA INSTRUMENTS TGA 2050
1–11
Introducing the TGA 2050
Table 1.3
Sampling System
Sample pans
Types
Volume capacity
Weighing capacity1
Platinum, Alumina
(Al203), Aluminum
Platinum: 50 µL,
100 µL
Alumina: 100 µL,
250 µL, 500 µL
Aluminum: 100 µL
1.0 gm
Balance measurement2
Resolution
0.2 µg
Accuracy
< + 0.1%
Ranges
100 mg range:
-10 mg to 100 mg
1000 mg range:
-100 mg to 1000 mg
t CAUTION:
1
The total mechanical
capacity of the balance is
5 gm. In order to avoid
damaging the balance
assembly, never allow the
total weight of the sample,
tare weight, hang-down
wires, and pans to exceed
5 gm.
2
The TGA balance mechanism is sensitive to changes
in the surrounding room
temperature. For optimum
accuracy, you must regulate
the ambient temperature.
(table continued)
1–12
TA INSTRUMENTS TGA 2050
Specifications
Table 1.3
Sampling System
(continued)
Furnace Atmosphere
Purge gases
Purge rate
!WARNING
TA INSTRUMENTS TGA 2050
Helium, nitrogen,
oxygen, air, argon3
Up to 100 cc/min
3
Do not use hydrogen or
any other explosive gas
in the TGA 2050. Oxygen may be used. However, the furnace must be
kept clean of hydrocarbons to prevent combustion.
1–13
Introducing the TGA 2050
1–14
TA INSTRUMENTS TGA 2050
CHAPTER 2: Installing the
TGA 2050
Unpacking/Repacking the 2050 .................. 2-3
Unpacking the 2050 ............................. 2-3
Repacking the 2050 .............................. 2-6
Installing the Instrument ............................ 2-7
Inspecting the System.......................... 2-8
Choosing a Location ........................... 2-9
Filling the Heat Exchanger................ 2-10
Connecting Cables and Lines ............ 2-12
Heat Exchanger Cable
and Water Lines .......................... 2-12
GPIB Cable ................................. 2-14
Purge Lines ................................. 2-17
Cooling Gas Line ........................ 2-19
Power Cable ................................ 2-20
Unpacking the Balance ............................ 2-21
Installing the Hang-Down Wires ....... 2-23
Aligning the Sample
Hang-Down Wire .............................. 2-27
Adjusting the Sample Platform ......... 2-31
TA INSTRUMENTS TGA 2050
2–1
Installing the TGA 2050
Starting the 2050 ....................................... 2-32
Shutting Down the Instrument .................. 2-33
2–2
TA INSTRUMENTS TGA 2050
Unpacking/Repacking the 2050
Unpacking/Repacking
the 2050
NOTE:
Due to the delicate mechanisms contained in the
TGA 2050 balance, the balance will be unpacked
later, see page 2-21.
Refer to Figures 2.1 to 2.3 while unpacking your
instrument.
Unpacking the
2050
!WARNING
Have an assistant help you unpack this
unit. Do not attempt to do this alone.
Figure 2.1
Shipping Boxes
TA INSTRUMENTS TGA 2050
2–3
Installing the TGA 2050
1. Open the shipping carton and remove the
accessory box.
2. Remove the cardboard packing insert.
3. Stand at one end of the box with your
assistant facing you at the other end. Lift
your end of the unit out of the box as your
assistant lifts his/her end.
4. Place the unit on a lab bench with one side
hanging over the edge of the bench (see
Figure 2.2). Someone must be holding
onto the unit at all times while it is in this
position.
Figure 2.2
Installing Mounting Feet
2–4
TA INSTRUMENTS TGA 2050
Unpacking/Repacking the 2050
5. While your assistant holds the unit, use a
wrench to remove the two nuts and washers
from the bottom. Then lift and rotate the
unit so that the other end hangs over the
edge of the bench. Someone must hold
onto the unit at all times while it is in this
position. While your assistant holds the
unit, remove the two nuts and washers from
the other side.
6. Slide the unit completely onto the lab bench.
Have your assistant hold one side up while
you unscrew and remove the black rubber
shipping feet from the bottom. Then rotate
the unit and remove the shipping feet from
the other side in the same manner.
7. Have your assistant lift one side of the unit
while you install two mounting feet on one
side (see Figure 2.3). Screw in about 1/4inch of the threaded mounting post into the
unit. Rotate the unit and install the two
remaining mounting feet on the unit in the
same manner.
8. Have your assistant lift the entire unit while
you slide the plywood board out from under
the unit.
9. Turn the instrument to face front and use a
wrench to remove the furnace clamp from
the unit. Retain this clamp in case the
instrument needs to be shipped in the future.
TA INSTRUMENTS TGA 2050
2–5
Installing the TGA 2050
Figure 2.3
Installing the
Mounting Feet
10. Follow the directions beginning on page 2-7
to install the instrument before you unpack
the balance.
Repacking
the 2050
To pack and ship your instrument, use the
hardware retained during unpacking and reverse
the instructions found on pages 2-3 to 2-5.
2–6
TA INSTRUMENTS TGA 2050
Installing the Instrument
Installing the
Instrument
Before shipment, the TGA 2050 instrument is
inspected both electrically and mechanically so
that it is ready for operation upon proper installation. Installation involves the following
procedures, described in this chapter:
•
•
•
•
•
•
•
•
•
Unpacking the instrument and its
components and accessory kit
Inspecting the system for shipping
damage and missing parts
Filling the heat exchanger
Connecting the TGA to the TA
Instruments controller
Connecting the heat exchanger cable and
water lines, purge gas lines, accessories,
and power cable
Unpacking the balance
Installing the hang-down wires
Leveling the instrument and aligning the
hang-down wires
Adjusting the sample platform.
If you wish to have your TGA installed by a TA
Instruments Service Representative, call for an
installation appointment when you receive your
instrument.
t CAUTION:
TA INSTRUMENTS TGA 2050
To avoid mistakes, read this entire chapter
before you begin installation.
2–7
Installing the TGA 2050
Inspecting
the System
When you receive your TGA, look over the
instrument and shipping container carefully for
signs of shipping damage, and check the parts
received against the enclosed shipping list.
If the instrument is damaged, notify the carrier
and TA Instruments immediately.
If the instrument is intact but parts are missing,
contact TA Instruments.
A list of TA Instruments phone numbers can be
found in Appendix A of this manual.
2–8
TA INSTRUMENTS TGA 2050
Installing the Instrument
Choosing a Location
Because of the sensitivity of TGA experiments,
it is important to choose a location for the
instrument using the following guidelines. The
TGA should be:
In
... a temperature controlled
area.
... a clean, vibration-free
environment.
... an area with ample working
and ventilation space.
(Refer to the specifications in
Chapter 1 for the instrument dimensions).
On
... a stable work surface.
Near
... a power outlet (115 volts AC, 50 or
60 Hz, 15 amps). A step up/down
line transformer may be required if
the unit is operated at a higher or
lower line voltage.
... your TA Instruments thermal
analysis controller.
... compressed lab air and purge gas
supplies with suitable regulators and
flow meters.
Away from
TA INSTRUMENTS TGA 2050
... dusty environments.
... exposure to direct sunlight.
... direct air drafts (fans, room air
ducts).
... poorly ventilated areas.
... noisy or mechanical vibrations.
2–9
Installing the TGA 2050
Drying out the instrument may be needed, if it has
been exposed to humid conditions. It is important
to be certain that the instrument ground is
adequately connected to the facilities ground for
safe operation.
NOTE:
Run the following method to dry out the instrument
(refer to Chapter 4 for further information):
1 Ramp at 10°C/min to 400°C
2 Isothermal for 30 min.
Filling the
Heat Exchanger
The heat exchanger contains a liquid reservoir
that supplies the instrument with coolant to
dissipate heat from the furnace. The coolant
exits the heat exchanger through the supply line,
circulates to the furnace, and comes back to the
reservoir via the return line as seen in Figure 2.4
(for instructions on how to connect the water
lines, turn to page 2-13). To fill the heat exchanger, follow the directions given below.
Heat
Exchanger
Cable
Figure 2.4
Rear Panel of
Heat Exchanger
Screws
1. Unscrew the water reservoir cap on the heat
exchanger bottle (see Figure 2.5).
2–10
TA INSTRUMENTS TGA 2050
Installing the Instrument
Fill to bottle's inner rim
Figure 2.5
Heat Exchanger Bottle
2. Pour one half bottle of TA Instruments TGA
Conditioner (PN 952377.001) into the water
reservoir bottle. Then fill the bottle to the
inner rim (see Figure 2.5) with distilled
water.
NOTE:
After the system has been started, recheck the
level of water in the reservoir bottle and refill to
the inner rim with distilled water, if necessary.
t CAUTION:
Do not put any water other than distilled
water in the heat exchanger reservoir.
3. Replace and tighten the water reservoir cap.
TA INSTRUMENTS TGA 2050
2–11
Installing the TGA 2050
Connecting
Cables and Lines
To connect the cables and water and gas lines,
you will need access to the TGA instrument’s
rear panel. All directional descriptions are
written on the assumption that you are facing the
back of the instrument.
NOTE:
Connect all cables before connecting the power
cords to outlets. Tighten the thumbscrews on all
computer cables.
t CAUTION:
Whenever plugging or unplugging power cords,
handle them by the plugs, not by the cords.
!WARNING
Protect power and communications cable
paths. Do not create tripping hazards by
laying them across accessways.
Heat Exchanger Cable
and Water Lines
1. Locate the cooling accessory connector on
the left rear of the instrument cabinet
(Figure 2.6).
2. Connect the heat exchanger cable to the
connector. The heat exchanger cable is the
only cable that fits into this connector.
2–12
TA INSTRUMENTS TGA 2050
Installing the Instrument
FUSE
FUSE
10 A
Cooling
Accessory
Connector
Figure 2.6
TGA Connector Panel
3. Remove the water lines from the packing.
4. Connect one end of the water line marked
“SUPPLY” to the connector labeled “SUPPLY” on the left front of the instrument
cabinet.
5. Connect the other end of the water line
marked “SUPPLY” to the connector labeled
“SUPPLY” on the heat exchanger.
6. Connect one end of the unmarked water line
to the connector labeled “RETURN” on the
left front of the instrument cabinet.
7. Connect the other end of the unmarked
water line to the connector labeled “RETURN” on the heat exchanger.
Figure 2.7 on the next page illustrates the
correct water line connections for the TGA
and heat exchanger.
TA INSTRUMENTS TGA 2050
2–13
Installing the TGA 2050
Figure 2.7
Heat Exchanger
Water Line
Connections
NOTE:
Air trapped in the heat exchanger system must be
purged before starting the first run. After installation of the TGA is complete, turn on the instrument by placing the HEATER and POWER switches
in the ON position. Then start the heat exchanger
pump by turning on Air Cool from the controller.
Refill the coolant reservoir as needed. Repeat this
process untill all of the air has been purged from
the system and the instrument stops reporting an
“Err 119.”
GPIB Cable
1. Locate the GPIB connector on the right rear
of the TGA instrument (See Figure 2.9).
2. Connect the GPIB cable to the connector.
The GPIB cable is the only cable that fits
into the connector.
3. Tighten the hold-down screws on the
connector.
2–14
TA INSTRUMENTS TGA 2050
Installing the Instrument
4. Connect the other end of the GPIB cable to
the controller or to the GPIB cable of
another TA Instruments instrument connected to the controller.
5. Select an address from 1 to 9. Then use the
binary address switches on the TGA connector panel to set the desired address (Table
2.1). Figure 2.8 shows a instrument address
of 7.
NOTE:
If you have a multi-instrument system, each
instrument must have a different address.
If you change the address after the TGA is
powered on, you must press the TGA’s Reset
button to enter the new address. Wait 30
seconds after releasing the Reset button; the
yellow ready light should begin to glow steadily.
Reconfigure the instrument.
TA INSTRUMENTS TGA 2050
2–15
Installing the TGA 2050
Table 2.1
Binary Address Settings*
Address
Switch Pattern
12345
1
2
3
4
5
6
7
8
9
00001
00010
00011
00100
00101
00110
00111
01000
01001
*0 = OFF; 1 = ON
ADDRESS
O
N
1
2
3
4
5
Figure 2.8
Binary Address Switches
2–16
TA INSTRUMENTS TGA 2050
Installing the Instrument
Purge Lines
!WARNING
Do not use any liquid in the purge lines.
1. Locate the PURGE and BALANCE PURGE
fittings on the back of the TGA instrument
(Figure 2.9).
FUSE
FUSE
Figure 2.9
TGA PURGE Fittings
TA INSTRUMENTS TGA 2050
2–17
Installing the TGA 2050
2. Make sure that the pressure of your purge
gas source does not exceed the manufacturers’ recommended pressures for flowmeters
and other regulated devices you are using.
NOTE:
If you are using laboratory purge, rather than
bottled purge, you will need to install an external
drier.
t CAUTION:
The use of corrosive gases in the TGA 2050 are
not recommended.
!WARNING
Use of an explosive gas as a purge gas is
dangerous and is not recommended for this
instrument. For a list of the purge gases
that can be used with the TGA instrument,
see Chapter 1. Oxygen may be used as a
purge gas, but the furnace must be kept clean
of volatile hydrocarbons to prevent combustion.
3. Connect a length of 1/4-inch I.D. flexible
tubing from each of the PURGE fittings to a
flowmeter (consult your compressed gas
vendor for specific requirements). Then
connect each flowmeter to the purge gas
source.
4. The recommended setting for the purge rate
is 100 cc per minute or less, with a flow
distribution of 10 percent to the balance
chamber and 90 percent to the furnace.
2–18
TA INSTRUMENTS TGA 2050
Installing the Instrument
Cooling Gas Line
1. Locate the COOLING GAS fitting, a 1/4inch compression fitting on the left side of
the TGA cabinet back, marked with a 120
psig maximum warning label (Figure 2.10).
FUS
E
FUSE
10 A
Figure 2.10
TGA COOLING
GAS Fitting
Cooling Gas Fitting
2. Make sure your compressed lab air source is
regulated to between 25 and 120 psig and is
free of oil and water vapors.
3. Connect a compressed lab air line to the
COOLING GAS fitting.
NOTE:
TA INSTRUMENTS TGA 2050
Nitrogen may also be used as a cooling gas.
2–19
Installing the TGA 2050
Power Cable
1. Make sure the TGA POWER switch, located
on the back of the instrument, (Figure 2.11)
is in the OFF position.
Power
Switch
FUS
E
FUSE
10 A
Figure 2.11
TGA POWER Switch
2. Plug the power cable into the TGA.
t CAUTION:
Before plugging the TGA power cable into the wall
outlet, make sure the instrument is compatible
with the line voltage. Check the label on the back
of the unit to verify the voltage.
3. Plug the power cable into the wall outlet.
2–20
TA INSTRUMENTS TGA 2050
Unpacking the Balance
Unpacking the
Balance
t CAUTION:
When unpacking the balance, be careful not to
damage the balance arm or hang-down loops.
1. Using the 7/64-inch ball driver supplied in
your TGA accessory kit, loosen and remove
the six screws securing the balance chamber
faceplate to the instrument.
2. Take off the faceplate.
3. Loosen and remove the thumbscrew holding
the balance cover on the sample (left) side
of the balance mechanism (Figure 2.12), and
take off the cover. Repeat this step for the
tare (right) side of the balance mechanism.
Tare
Side
Sample
Side
Balance
Cover
Balance
Cover
Screw
Figure 2.12
Interior of
Balance Chamber
Before Unpacking
TA INSTRUMENTS TGA 2050
Hang-Down
Loop
Tare
Tube
2–21
Installing the TGA 2050
4. Using tweezers, remove the foam insert
from around the screw hole (Figure 2.13):
a.
Gently compress the foam with the
tweezers, being careful not to touch the
balance.
b. Remove the foam insert from the
balance chamber.
Figure 2.13
Removal of
Foam Insert
from Balance Chamber
Foam
Insert
5. Replace the sample side cover and screw.
6. Repeat the procedure to remove the foam
insert in the tare (right) side of the balance.
2–22
TA INSTRUMENTS TGA 2050
Installing the Hang-Down Wires
Installing the
Hang-Down Wires
t CAUTION:
During installation, take care not to bend the
hang-down wires or damage the hang-down loops.
1. Turn on the TGA instrument (see Chapter 3
for proper start-up order).
2. Press the FURNACE key to lower the
furnace.
3. Locate the sample hang-down wire in your
TGA Accessory Kit.
4. Hold the wire in your hand so that the
doubly bent top hook is pointing to the left
and the bottom hook is pointing to the right.
5. Carefully insert the bottom of the hangdown wire into the top of the furnace far
enough so that you can insert the top of the
wire into the hang-down tube without
bending the wire (Figure 2.14 on the next
page).
TA INSTRUMENTS TGA 2050
2–23
Installing the TGA 2050
Hang-Down
Tube
Figure 2.14
Installing the Sample
Hang-Down Wire
6. Thread the hang-down wire up through the
hang-down tube into the balance chamber,
and hook the top of the wire over the top of
the tube (see Figure 2.15 on the next page).
NOTE:
To make the hang-down loops easier to see, we
suggest sliding a piece of white paper into the
balance chamber behind each loop before you hook
the hang-down wire into it. (Do not forget to
remove the paper when finished.)
7. Grasp the top hook of the hang-down wire
with brass tweezers. Being careful to keep
the top hook pointing to the left, pass the
double bend through the hang-down loop so
the wire is hanging from the loop.
8. Unscrew and remove the tare tube.
2–24
TA INSTRUMENTS TGA 2050
Installing the Hang-Down Wires
Figure 2.15
Installing the Tare
Hang-Down Wire
TA INSTRUMENTS TGA 2050
2–25
Installing the TGA 2050
9. Locate the tare hang-down wire in your
accessory kit.
10. Hold the wire in your hand so that the
doubly bent top hook is pointing to the left
and the bottom hook is pointing to the right.
11. Using brass tweezers, insert the tare hangdown wire into the balance chamber on the
tare side and down through the hole above
the tare tube connection, taking care not to
bend the wire.
12. Being careful to keep the top hook pointing
to the left, pass the double bend through the
hang-down loop so the wire is hanging from
the loop.
13. Select the sample pan you will use in your
experiments and load one of the same size
and type onto the tare hang-down wire.
14. Replace the tare tube and finger-tighten it to
compress the O-ring seal.
You are now ready to align the hang-down
wires.
2–26
TA INSTRUMENTS TGA 2050
Installing the Hang-Down Wires
Aligning the Sample
Hang-Down Wire
To avoid weight signal noise, the TGA instrument must be level so that the sample pan and
hang-down wire hang inside the furnace and
hang-down tube without touching them. The
angle at which the pan hangs is very sensitive to
slight irregularities in benchtop surfaces, so it is
important that you select a sturdy table or bench
for your TGA.
Once you have your TGA in a satisfactory
location, adjust the top and bottom of the sample
hang-down wire and level the instrument using
the following procedures.
To align the top of the sample hang-down wire:
1. Place an empty sample pan on the sample
platform.
2. Press the LOAD key on the instrument
keypad. The TGA will automatically lower
the furnace (if necessary), move the sample
platform over to the furnace, and load the
pan onto the balance.
If the pan will not automatically load, place
the pan manually (using brass tweezers) on
the sample hang-down wire and continue
with the procedure. Use the Sample Platform Adjust procedure (page 2-31) to
correct loading after completing sample
hang-down wire alignment.
TA INSTRUMENTS TGA 2050
2–27
Installing the TGA 2050
3. Check to see whether the top end of the
sample hang-down wire is hanging freely
and roughly centered within the top of the
hang-down tube inside the balance chamber.
4. If the wire is not roughly centered inside the
hang-down tube, turn the balance adjustment screw (Figure 2.16) with the 7/64-inch
ball driver until the wire is centered.
Turning the balance adjustment screw
clockwise will move the wire backwards;
turning the screw counterclockwise will
move the wire frontwards.
Balance
Adjustment
Screw
Hang-Down
Loop and
Wire
Figure 2.16
Location of Balance
Adjustment Screw
2–28
Top of
Hang-Down
Tube
TA INSTRUMENTS TGA 2050
Installing the Hang-Down Wires
To align the bottom of the hang-down wire:
1. Press the FURNACE key to raise the
furnace just to the bottom of the sample pan,
and press STOP.
2. Check the alignment of the sample pan
within the furnace. It should hang freely,
roughly centered, and should not be touching the sides of the furnace or the hangdown tube (Figure 2.17).
3. If the sample pan is not centered and hanging freely within the furnace, level the TGA
instrument by adjusting the feet on the
bottom. Turn the feet clockwise to lengthen
or counterclockwise to shorten the legs.
Continue adjusting until the pan hangs
correctly.
TA INSTRUMENTS TGA 2050
2–29
Installing the TGA 2050
Hang-Down
Tube
Furnace
Housing
Sample
Pan
Figure 2.17
Aligning the Sample
Pan in the Furnace
4. Press the FURNACE key to lower the
furnace.
5. Press the UNLOAD key to remove the
sample pan from the furnace.
6. Replace the balance chamber faceplate and
its 6 screws.
If you had to load the sample pan manually
in order to align it in the furnace, you should
now adjust the sample platform using the
procedure described on the next page.
2–30
TA INSTRUMENTS TGA 2050
Installing the Hang-Down Wires
Adjusting the
Sample Platform
If the sample hang-down wire fails to pick up a
sample pan during an automatic loading procedure, you will need to adjust the position of the
sample platform, using the Sample Platform
Adjust procedure. This procedure is part of TGA
instrument control, see the online help and
documentation for further information.
TA INSTRUMENTS TGA 2050
2–31
Installing the TGA 2050
Starting the
TGA 2050
NOTE:
Allow the TGA to warm up for at least 30 minutes
before performing an experiment.
1. Check all connections between the 2050 and
the controller. Make sure each component is
plugged into the correct connector. (For
installation information, see Chapter 2.)
2. Press the instrument power switch, located
on the rear of the instrument, to the ON
position. The green power light on the front
of the instrument should turn on and the
yellow Ready light should flash.
3. If the green power light fails to come on,
recheck the power connections to the
instrument and the power source. Also,
check instrument power fuse F1 on the rear
of the instrument to see if the fuse is blown.
2–32
TA INSTRUMENTS TGA 2050
Shutting Down the Instrument
Shutting Down
the Instrument
Before you decide to power down your TGA
instrument, consider the following:
•
All of the components of your thermal
analysis system are designed to be powered
on for long periods.
•
The electronics of the TGA and the
controller perform more reliably if power
fluctuations caused by turning units on and
off are minimized.
For these reasons, turning the system and its
components on and off frequently is discouraged.
When you finish running an experiment on your
TGA and wish to use the thermal analysis
system for some other task, leave the instrument
on; it will not interfere with whatever else you
wish to do.
If you do need to power down your instrument
for any reason, simply press the POWER switch
to the OFF (0) position.
TA INSTRUMENTS TGA 2050
2–33
Installing the TGA 2050
2–34
TA INSTRUMENTS TGA 2050
CHAPTER 3: Running Experiments
Overview .................................................... 3-3
Before You Begin ............................... 3-4
Calibrating the TGA ................................... 3-5
Temperature Calibration ...................... 3-5
Weight Calibration ............................... 3-6
Running a TGA Experiment ....................... 3-6
Experimental Procedure ....................... 3-6
Preparing the Sample .......................... 3-7
Selecting Sample
and Tare Pans ................................ 3-7
Taring the Sample Pan ................... 3-8
Automatic Tare ....................... 3-9
Manual Tare ............................ 3-9
Loading the Sample ............................ 3-10
Setting Up an Experiment .................. 3-14
Setting Up Accessories ..................... 3-15
Using a Purge Gas ....................... 3-15
Using the Air Cool Option .......... 3-18
Using the Gas Switching
Accessory .................................... 3-18
Starting an Experiment ....................... 3-20
TA INSTRUMENTS TGA 2050
3–1
Running Experiments
Stopping an Experiment ..................... 3-21
Unloading the Sample ................. 3-22
Use in an Oxygen-Free Atmosphere ......... 3-23
Purge Gas System............................... 3-23
Instrument Setup ................................ 3-24
3–2
TA INSTRUMENTS TGA 2050
Overview
Overview
All of your TGA experiments will have the
following general outline. In some cases, not all
of these steps will be performed.
•
•
•
•
•
•
•
Entering experiment information through
the TA controller (sample and instrument
information)
Creating and loading the thermal method on
the controller
Attaching and setting up external
accessories as required (e.g., purge gas, air
cool, gas switching accessory)
Selecting and taring the sample pan
Loading the sample
Starting the experiment
Unloading the sample at the end of the
experiment.
To obtain accurate results, follow procedures
carefully and check calibration periodically
(once a month). Consult the online help and
documentation for details on calibrating the
TGA and conducting experiments.
TA INSTRUMENTS TGA 2050
3–3
Running Experiments
Before You Begin
Before you set up an experiment, ensure that the
TGA and the controller have been installed
properly. Make sure you have:
•
•
•
•
•
•
•
•
3–4
Made all necessary cable connections
between the TGA and the controller
Connected heat exchanger cable and water
lines
Connected all gas lines
Powered on each unit
Installed all appropriate options
Configured the instrument online with the
controller
Become familiar with controller operations
Calibrated the instrument, if necessary.
TA INSTRUMENTS TGA 2050
Calibrating the TGA
Calibrating the TGA
The TGA 2050 requires two kinds of calibration: temperature calibration and weight calibration. Both of these calibrations should be
performed when you first install the instrument
and at least once a month thereafter. Consult the
see the online help and documentation for
further information.
Temperature
Calibration
Temperature calibration involves analyzing a
material for its Curie Temperature, and comparing the observed value with the standard literature value. The standard most often used is
nickel with a curie temperature of 354.4°C
(NIST Certificate for GM761). The Curie
Temperature corresponds to the extrapolated
endpoint on the "s-shaped" thermal curve
generated utilizing a magnet.
Figure 3.1
Curie Temperature
Determination
TA INSTRUMENTS TGA 2050
3–5
Running Experiments
Weight Calibration
TGA weight calibration uses standard reference
weights to calibrate the accuracy of the TGA
balance system. This calibration is conducted
through the controller.
Running a
TGA Experiment
Experimental Procedure
All of your TGA experiments will have the
following general outline.
3–6
•
Selecting and preparing a sample. This
involves preparing a sample of the
appropriate size, selecting the sample cup,
and placing the sample in the cup.
•
Taring and loading the sample cup on the
balance.
•
Entering experimental information through
the TA controller.
•
Creating and selecting the thermal method
on the controller.
•
Setting up any external accessories.
•
Starting the experiment.
TA INSTRUMENTS TGA 2050
Running an Experiment
Preparing the Sample
Selecting Sample
and Tare Pans
Three kinds of sample pans are available for the
TGA 2050: platinum, alumina ceramic, and
aluminum. The platinum pans come in 50 and
100 µL sizes, the ceramic pans come in 100,
250, and 500 µL sizes, and the aluminum pans
are 100 µL in size. The criteria for choosing a
sample pan are as follows:
TA INSTRUMENTS TGA 2050
•
For most experiments, platinum is the
desirable choice. It is easy to clean and does
not react with most organics and polymers.
Ceramic pans are more porous and are
therefore more easily contaminated. There
are some conditions, however, in which
other types of pans are desirable, as
explained below.
•
Use ceramic pans for samples that might
amalgamate or react with platinum (e.g.,
metals, corrosives, inorganics).
•
Use aluminum pans when disposability is
desired. Aluminum pans are meant for one
time use in experiments that do not go
above 600°C and for samples that do not
react with aluminum (e.g., corrosives, acidic
materials, or anything that would alloy with
aluminum).
•
If your sample will melt during the experiment, use a pan that is deep enough to
prevent spilling (the deepest pan is the
500 µL ceramic pan).
3–7
Running Experiments
The platinum and ceramic pan types are reusable. To clean between experiments, use a
Bunsen burner or a propane torch, or run the pan
through a hot thermal program in the TGA to
burn out any residue. Aluminum pans are
disposable, do not attempt to clean and reuse
them.
Once you have selected the proper sample pan,
remove the tare tube, and using brass tweezers,
put the same type and size pan on the tare hook.
NOTE:
Whenever a different type of pan is selected, the
balance must be mechanically tared using step 1
of the weight calibration.
Taring the
Sample Pan
Taring the sample pan ensures that the weight
measured by the balance reflects the weight of
the sample only. You should tare the sample pan
before each experiment, even if you use the
same pan in consecutive experiments.
When you tare a pan, the TGA reads the weight
of the empty pan and then stores the weight as
an offset, which is subtracted from subsequent
weight measurements. For optimum accuracy,
the weight reading must be stable before it is
accepted as an offset. If you use the automatic
tare procedure, the TGA will determine when
the weight reading is sufficiently stable; or you
can determine the acceptability of the weight
reading by taring the system manually. Both tare
procedures are explained here.
3–8
TA INSTRUMENTS TGA 2050
Running an Experiment
Automatic Tare
Because the TGA 2050 has two weight ranges,
taring is done for both ranges. The tare weight is
stored by the instrument for both weight ranges.
1. Place the empty sample pan on the sample
platform.
2. Press the TARE key on the instrument
keypad or from the controller. The TGA will
automatically load the pan, raise the furnace
(to protect the pan from air currents), weigh
the pan, store the weight as the offset for
each weight range, and unload the pan.
Manual Tare
Manual tare operates in the weight range
indicated, by storing the current reading as an
offset, and estimates the tare weight for the other
weight range (typically the 1-gm range). The
estimate is accurate if the TGA 2050 has been
tared or weight-calibrated recently.
1. Place the empty sample pan on the sample
platform.
2. Press the LOAD key to load the pan onto the
balance.
3. Press the FURNACE key to close the
furnace, to protect the pan from air currents.
4. Observe the weight reading on the
controller's Signal Display window screen
(Signal A Weight).
5. Wait for the Signal A Weight to stabilize,
and then choose Auto Zero to store the
displayed weight as the offset.
6. Press the UNLOAD key to open the furnace
and unload the pan.
TA INSTRUMENTS TGA 2050
3–9
Running Experiments
Loading the Sample
After taring the sample pan, load the sample into
the TGA furnace as follows:
1. Place the sample in the sample pan, and
position the pan on the sample platform
(Figure 3.2).
The wire on the bottom of the sample pan
should align with the groove in the panhole,
so that the sample pan can be picked up by
the sample hang-down wire.
NOTE:
Always use brass tweezers to handle the sample
pans.
t CAUTION:
Manually loading the sample pan onto the hangdown wire may damage the balance mechanism.
Figure 3.2
Sample Pan
Ready to Load
3–10
TA INSTRUMENTS TGA 2050
Running an Experiment
2. Press the LOAD key. The TGA will automatically load the sample pan onto the
balance.
3. Position the thermocouple at the edge of the
sample pan, rather than in the middle, for
best results (Figure 3.3).
NOTE:
The position of the thermocouple should be the
same as it was during temperature calibration.
Thermocouple
Sample
Hook
Figure 3.3
Adjusting the
Thermocouple
TA INSTRUMENTS TGA 2050
Thermocouple
should be
about2mm
from the pan
surface.
Sample Pan
3–11
Running Experiments
4. Press the FURNACE key to close the
furnace by moving it up around the sample,
until it is fully closed as shown in Figure
3.4.
Figure 3.4
Furnace Closing
3–12
TA INSTRUMENTS TGA 2050
Running an Experiment
Figure 3.5
Furnace in
Fully Closed Position
TA INSTRUMENTS TGA 2050
3–13
Running Experiments
Setting Up an
Experiment
Once you have prepared the sample, the next
step in your experiment is to enter the needed
information in the TA controller. All of the
controller functions described in this section are
accessed through the Instrument Control screen.
Refer to the online help and documentation to
learn how to perform the following steps.
1. Select the Instrument.
2. Select the Instrument Mode.
3. Enter Sample Information.
4. Enter Instrument Information.
5. Create and Select Thermal Methods.
The first time you use your TGA you will need
to create at least one thermal method to control
experiments. Each method is made of several
segments, or individual instructions (e.g.,
Equilibrate, Ramp), that control the state of the
instrument.
3–14
TA INSTRUMENTS TGA 2050
Running an Experiment
Setting Up
Accessories
If your experiment requires external accessories,
ensure that they are turned on, and make any
necessary adjustments before you start your
experiment. Make sure that the system can
achieve the conditions of all segments in the
method.
This section describes how to use the following
accessories with the TGA 2050:
•
•
•
Air cool option
Purge gas
TA Instruments Gas Switching Accessory.
The TGA can also be used with other accessories, such as vacuum, FTIR, gas chromatographs, mass spectrometers, and evolved gas
analyzers. Consult the appropriate local instrument manufacturer for further information.
Using a
Purge Gas
You can control the sample atmosphere during
TGA experiments by connecting a purge gas to
the system. Purge gas is distributed separately
to two parts of the TGA: the furnace and the
balance chamber.
The balance purge maintains a positive pressure
in the balance chamber to prevent decomposition products from contaminating the sensitive
balance mechanism. The balance purge flows
from the balance chamber via two routes: down
TA INSTRUMENTS TGA 2050
3–15
Running Experiments
the hang-down tube and through an outlet in the
balance chamber to the right of the hang-down
tube. It then exits across the sample pan along
with the furnace purge.
The purge flow through the furnace is horizontal
to the sample (Figure 3.6), permitting rapid
removal of decomposition products from the
sample environment.
Figure 3.6
Furnace Purge
You can choose nitrogen, oxygen, helium, air, or
argon for your purge environment. Do not use
any other gases in the TGA 2050.
!WARNING
Do not use hydrogen or any other explosive
gas in the TGA 2050 furnace. Oxygen may be
used as a purge gas, but the furnace must be
kept clean of volatile hyrdrocarbons to prevent
combustion.
!WARNING
Do not use any liquid in the purge lines.
3–16
TA INSTRUMENTS TGA 2050
Running an Experiment
Purge gas can be obtained from a pressurized
cylinder or an in-house supply source. Gas
supplied from an in-house source should be
passed through a sieve dryer to remove any trace
of moisture before in enters the TGA.
It is important to maintain the proper ratio of
flow rates between the balance chamber and the
furnace housing. Having the separate balance
chamber purge prevents decomposition gases
from entering the balance chamber. The recommended setting for the purge rate is 100 cc per
minute or less. The flow distribution should be
10 percent to the balance chamber and 90
percent to the furnace.
To maintain this flow distribution, you will need
to connect a flowmeter to each of the purge
fittings on the back of the TGA instrument. Set
the purge gas flow rates by adjusting these
meters. The PURGE port goes to the TGA
furnace, and the BALANCE PURGE goes to the
balance chamber.
Before you start the purge gas, make sure that
the desired gas is connected to the purge ports,
that all lines are clear, and that your supply of
purge gas is sufficient for the experiment.
Always maintain constant purge flow rates and
distribution throughout your experiment;
changing the purge during an experiment can
affect the data.
TA INSTRUMENTS TGA 2050
3–17
Running Experiments
Using the Air
Cool Option
You can program the system to air cool the
furnace automatically at the end of the experiment by selecting this option from the TA
controller. After the air cool is activated, it will
continue to run for the desired time.
Before you start an experiment that uses the air
cool option, ensure that the supply valve from
the air source is open and that the pressure is
regulated to between 25 and 120 psig. Nitrogen
can also be used as a cooling gas.
NOTE:
Air Cool can be used with the furnace closed.
However, if the temperature is above 500°C, the
furnace will cool naturally until it is 500°C or less,
then Air Cool will begin.
Using the Gas
Switching Accessory
You can use the Gas Switching Accessory to
turn the purge gas on and off or to switch
between two different purge gases during a TGA
experiment. Before starting an experiment that
uses the Gas Switching Accessory, make sure its
power switch is on, and make sure the necessary
gas sources are properly connected.
The Gas Switching Accessory can be controlled
by the Gas segment in the method (see the
online help and documentation) or by the Gas
control option.
3–18
TA INSTRUMENTS TGA 2050
Running an Experiment
Connect the Gas Switching Accessory to the
purge port only, when switching between gases
during an experiment. Attach the inert gas to
GAS 1 and the other gas to GAS 2.
Consult your Gas Switching Accessory
operator’s manual for further instructions.
TA INSTRUMENTS TGA 2050
3–19
Running Experiments
Starting an
Experiment
You can begin the experiment using either the
START key on the TGA instrument keypad or
select Start on the controller. When you start,
the system automatically begins the set-up
procedures. It loads the sample pan and closes
the furnace, if necessary, and then begins the
selected method and data collection starts.
If you wish to start collecting data during
instrument setup, you can use the forced start
feature. This is most useful for samples that
loose a significant amount of weight during the
set-up period (i.e., samples with volatile solvents). When a forced start is initiated, the
current sample weight is stored as the initial
weight, data collection is started immediately,
and the instrument status changes from “Set Up”
to “Started.” The method begins when the
normal set-up procedures are completed.
NOTE:
Once the experiment is started, operations are
best performed at the controller keyboard. The
TGA 2050 is very sensitive to motion and might
pick up the vibration caused by pressing a key on
the instrument keypad.
Forced Start
Press the START key on the instrument keypad
while the controller status line displays “Set
Up.”
3–20
TA INSTRUMENTS TGA 2050
Running an Experiment
Stopping an
Experiment
If for some reason you need to discontinue the
experiment, you can stop it at any point by using
either the STOP key on the TGA instrument
keypad or Stop on the controller screen. Another
function that stops the experiment is Reject on
the controller. However, the Reject function
discards all of the data from the experiment; the
Stop function saves any data collected up to the
point at which the experiment was stopped.
NOTE:
The Heat Exchanger will continue to run as long as
the Air Cool option is activated or until the indicated temperature is below 50oC.
t CAUTION:
The REJECT function discards all experiment
data.
TA INSTRUMENTS TGA 2050
3–21
Running Experiments
Unloading the Sample
If you select the “Furnace Open and Unload”
method-end option on the controller, the TGA
will automatically unload the sample at the end
of the run. If you need to unload the sample
manually, wait until the run and all method-end
operations are complete, and then press the
UNLOAD key. The sample pan may not line up
with the sample platform groove at method end.
3–22
TA INSTRUMENTS TGA 2050
Use in an Oxygen-Free Atmosphere
Use in an
Oxygen-Free
Atmosphere
A few extra precautions are necessary to ensure
an oxygen-free environment.
Purge Gas System
•
Use a high purity, inert gas of grade 5 or
better. It may be necessary to use an
oxygen trap in-line, depending on the purity
grade.
•
Choose a 2-stage regulator of diaphragm
construction for high purity applications.
•
Use copper or stainless steel tubing from
the gas regulator, to the flowmeters, and to
the TGA purge inlet ports.
•
Allow the TGA to prepurge (under closed
conditions) for at least 30 minutes after first
turning on your purge gas. Increase the
standard purge rate during this time.
100 cc/minute flow into the balance
chamber and 100 cc/minute into the
furnace.
TA INSTRUMENTS TGA 2050
3–23
Running Experiments
Instrument Setup
•
Readjust your flowmeter(s) for standard
operating flow rates.
10 cc/minute flow into balance chamber and
90 cc/minute into the furnace.
NOTE:
3–24
•
Tare sample pan (as needed).
•
Load sample and close system
•
Purge 20 minutes, if possible, before
starting a run.
•
When run is complete, allow the furnace to
cool in the closed position. This can be
done by changing the method-end
conditions to leave the furnace closed at
method end.
•
When using air or oxygen during an
experiment, introduce new gas through
furnace purge port only and switch back to
the inert gas before cooling down.
When the TGA is idle, leave the system closed and
continue purging with the inert gas.
TA INSTRUMENTS TGA 2050
CHAPTER 4: Technical Reference
Description of the TGA 2050 .................... 4-3
Components .......................................... 4-5
Balance .......................................... 4-6
Sample Loading Assembly ............ 4-8
Furnace .......................................... 4-9
Cabinet ......................................... 4-11
Heat Exchanger ............................ 4-13
Theory of Operation ................................. 4-14
Status Codes ............................................ 4-15
TA INSTRUMENTS TGA 2050
4–1
Technical Reference
4–2
TA INSTRUMENTS TGA 2050
Description of the TGA 2050
Description of
the TGA 2050
The TGA 2050 operates on a null balance
principle. Physically attached to a taut-band
meter movement, the balance arm is maintained
in a horizontal reference position by an optically
actuated servo loop. When the balance is in a
null position, a flag located on top of the balance
arm blocks an equal amount of light to each of
the photodiodes (the light is supplied by a
constant current infrared LED). As sample
weight is lost or gained, the beam becomes
unbalanced, causing an unequal amount of light
to strike the photodiodes. The unbalanced
signal, called the error signal, is acted upon by
the control circuitry and reduced to zero, or
nulled. This is accomplished by an increase or
decrease in the current to the meter movement,
causing it to rotate back to its original position
(null position). The change in current necessary
to accomplish this task is directly proportional to
the change in mass of the sample. This current
is converted to the weight signal.
The TGA 2050 has two weight ranges: 1 gm and
100 mg. Both ranges are continuous over their
weight loss operating range, which means that
the entire weight loss range can be viewed
without any loss of information. The weight loss
operating ranges are:
•
•
1 gm to 0 µg for the 1 gm range
100 mg to 0 µg for the 100 mg range.
Negative weight (tare imbalance) is limited to
150 mg in the 1 gm range, and to 15 mg in the
100 mg range. Range control is automatic.
TA INSTRUMENTS TGA 2050
4–3
Technical Reference
During normal operation of the TGA, the sample
may evolve gases. To prevent back diffusion of
these liberated gases to the balance chamber, the
balance chamber is purged with an inert gas (10
cc/min). An inert gas must be used to prevent
contamination or corrosion of the balance.
Heating rate and sample temperature are measured by the thermocouple located above the
sample. This enables the controller to program
and maintain the sample environment at your
selected rate.
4–4
TA INSTRUMENTS TGA 2050
Description of the TGA 2050
Components
The TGA 2050 has five major components,
illustrated in Figure 4.1: the balance, the sample
loading assembly, the furnace, the cabinet, and
the heat exchanger.
Balance
Chamber
Sample
Loading
Assembly
Thermocouple
Heat
Exchanger
Furnace
Keypad
Cabinet
Power
Light
Ready
Light
Figure 4.1
TGA 2050 Components
The balance, the most important part of the
TGA system, provides precise measurement of
the sample weight. The sample loading assembly automatically loads and unloads samples
from the TGA balance. The furnace controls the
sample atmosphere and temperature. The
cabinet contains the system electronics and
mechanics. The heat exchanger dissipates heat
from the furnace.
TA INSTRUMENTS TGA 2050
4–5
Technical Reference
Balance
The TGA balance assembly (shown in Figure
4.2 below) consists of the balance meter movement, the balance arm, the balance arm sensor,
the hang-down wire assemblies, the sample pan,
and the tare pan.
Balance Arm
Sensor
Hang-Down
Wire
Assembly
Balance
Arm
Balance Meter
Movement
Sample
Pan
Tare Pan
Figure 4.2
TGA Balance Assembly
The balance meter movement is a taut-band
meter movement to which the balance arm is
attached.
The balance arm is a rhombic piece of aluminum attached to the meter movement. It is in a
null balance system. A hang-down loop is
attached to each end to hold the hang-down
wires.
4–6
TA INSTRUMENTS TGA 2050
Description of the TGA 2050
The balance arm sensor is a printed circuit
board assembly that detects the null position of
the meter movement. The balance beam sensor
is mounted above the balance arm. It is used in
conjunction with the analog circuitry to maintain
a null position.
The TGA has two hang-down wire assemblies:
one for the tare pan and one for the sample pan.
Each assembly consists of a hang-down wire and
loop. The hang-down wire has hooks at each end
and connects the pan to the loop. The loop has
eyelets at each end; it is used to connect the
hang-down wire to the balance arm. The longer
hang-down wire (4 inches) is for the sample pan.
Sample pans are available in platinum in 50 and
100 µL sizes, alumina ceramic in 100, 250, and
500 µL sizes, and aluminum in 100 µL size. All
pans are 0.4 inch in diameter.
The tare pan holds the counterbalance weight
that mechanically subtracts out the weight of the
sample pan.
TA INSTRUMENTS TGA 2050
4–7
Technical Reference
Sample Loading Assembly
The sample loading assembly (Figure 4.3) is a
platform that pivots the sample pan to the
furnace area, where the pan engages the hangdown wire from the balance assembly. It also
pivots the platform away from the furnace area
for easy sample loading and unloading.
Figure 4.3
Sample Loading
Assembly
4–8
TA INSTRUMENTS TGA 2050
Description of the TGA 2050
Furnace
The TGA furnace consists of a quartz glass
sample tube surrounded by an electric resistance
heater, both of which are contained within a
water-cooled furnace housing. The housing is
mounted to a furnace base that raises and
lowers the furnace for sample loading and
unloading. See Figure 4.4.
Figure 4.4
Furnace
The sample tube has a purge gas inlet that
passes through the right side of the furnace
housing. A fitting on the left side of the housing
allows connection of a transfer line to carry
exhaust gas to a spectrometer such as a FTIR.
Because the heater is external to the sample
tube, evolved gases from sample decomposition
within the sample tube do not come in contact
with the resistance elements or the furnace
ceramic refractory.
TA INSTRUMENTS TGA 2050
4–9
Technical Reference
Cooling air enters through the furnace base and
passes upward between the outside of the
sample tube and the inside of the furnace,
completely separating the cooling air from the
sample and the sample zone.
The furnace is a resistance heater wound on
alumina ceramic, which allows sample zone
temperatures as high as 1000°C with heating
rates up to 50°C/min.
A Platinel II* thermocouple is positioned in the
furnace, just above the sample pan, where it
monitors the sample environment temperature.
The furnace base moves the furnace assembly
up around the sample pan to the closed position,
or down away from the sample pan to the open
position.
*
4–10
Platinel II is a registered trademark of
Engelhard Industries.
TA INSTRUMENTS TGA 2050
Description of the TGA 2050
Cabinet
The TGA cabinet (Figure 4.5) consists of the
cabinet housing, the keypad, the electronics
compartment, the purge and cooling gas fittings,
and the rear panel.
FUSE
FUSE
Figure 4.5
TGA Cabinet
Components
The TGA cabinet housing consists of a base
and a rear cover. The base is a single piece of
heavy-weight aluminum, designed to provide a
stable platform for the TGA instrument parts.
The TGA instrument keypad is described in
Chapter 1.
The electronics compartment contains the
electronics that control the instrument functions.
Two purge fittings are located on the back of
the instrument, one for the balance chamber and
one for the furnace housing.
TA INSTRUMENTS TGA 2050
4–11
Technical Reference
The cooling gas fitting is located on the left
side of the instrument back and is for furnace
cool-down air.
The rear panel (Figure 4.6) has the signal and
power connections for the instrument; the fuses;
the ready light; the POWER switch; the address
switches; the purge, gas, cooling accessory, and
GPIB connections; and the Reset button.
FUSE
FUSE
Figure 4.6
Rear Panel
4–12
TA INSTRUMENTS TGA 2050
Description of the TGA 2050
Heat Exchanger
The heat exchanger (Figure 4.7) consists of a
fan, a radiator, a water reservoir, a pump, a
temperature switch, and a flow switch.
The fan blows cool air through the radiator.
The radiator exchanges heat between the water
and air.
The water reservoir holds additional water that
may be required by the system.
The pump circulates the water through the
system.
The temperature switch detects over-temperature conditions, which could be caused by
failure of the fan.
The flow switch detects lack of flow, which
could be caused by failure of the pump or a leak
or blockage in the system.
Water Reservior
Bottle
Figure 4.7
Heat Exchanger
TA INSTRUMENTS TGA 2050
Temperature
Switch
Radiator
Flow Swtich
Fan
Pump
4–13
Technical Reference
Theory of
Operation
Thermogravimetric analysis (TGA) is a thermal
analysis technique for measuring the amount and
rate of change in sample mass as a function of
temperature and time. It is used to characterize
any material that exhibits weight loss or phase
changes as a result of decomposition, dehydration, and oxidation. Two modes are commonly
used for investigating thermal stability behavior
in controlled atmospheres: (1) dynamic, in
which the temperature is increased at a linear
rate, and (2) isothermal, in which the temperature is kept constant.
4–14
TA INSTRUMENTS TGA 2050
Status Codes
Status Codes
Status codes are continuously displayed at the top
of the controller screen.
Table 4.1
Method Status Codes
Code
Meaning
Air Cool
The furnace air cool line
has been opened to cool
the furnace.
Calib
The TGA Calibration
program is running.
Closing
The furnace assembly is
closing.
Cold
The instrument heater
cannot supply heat fast
enough to keep up with
the thermal program. This
may be caused by a large
ballistic jump in the
program, a faulty heater,
or a faulty control thermocouple signal.
Complete
The thermal method has
finished.
(table continued)
TA INSTRUMENTS TGA 2050
4–15
Technical Reference
Table 4.1
Method Status Codes
(continued)
4–16
Code
Meaning
Cooling
The heater is cooling, as
specified by a Ramp
segment.
Ending
The method is complete
and the furnace is cooling
until it can Air Cool or
open and unload.
Equilb
The temperature is being
equilibrated to the desired
set point.
Heating
The heater temperature is
increasing, as specified by
a Ramp segment.
Holding
Thermal experiment
conditions are holding;
the program is suspended.
Select Resume to continue the run.
Hot
The temperature is
beyond the set point, and
the instrument cannot
remove heat fast enough
to follow the thermal
program. This is usually
caused by a large ballistic
jump to a lower temperature.
(table continued)
TA INSTRUMENTS TGA 2050
Status Codes
Table 4.1
(continued)
TA INSTRUMENTS TGA 2050
Code
Meaning
Initial
The temperature is being
equilibrated to the desired
set point. When the
temperature has reached
equilibrium, the status
will change to “Ready.”
Iso
The thermal program is
holding the current
temperature isothermally.
Jumping
The heater is jumping
ballistically to the set
point temperature.
Load
The TGA is loading a
sample pan onto the
balance.
No Power
No power is being applied
to the heater. Check the
heater fuse.
Opening
The furnace assembly is
opening.
Ready
The system has equilibrated at the initial
temperature and is
ready to begin the next
segment. Use the Start
function to continue the
method.
(table continued)
4–17
Technical Reference
Table 4.1
Method Status Codes
(continued)
Code
Meaning
Reject
The experiment has been
terminated and the data
erased.
Repeat
The method is executing a
repeat loop that does not
involve temperature
control segments.
Set Up
The system is loading the
sample, closing the
furnace, and letting the
weight stabilize before
beginning the first segment.
Stand by
The method and methodend operations are complete.
Started
The TGA is still setting
up to start the experiment
(see Set Up above), but
the initial weight has been
measured and data collection has begun. The
thermal method will
start when the normal
setup process has been
completed.
(table continued)
4–18
TA INSTRUMENTS TGA 2050
Status Codes
Table 4.1
(continued)
TA INSTRUMENTS TGA 2050
Code
Meaning
Tare
The TGA is measuring
the weight difference
between an empty sample
pan and the tare pan. The
measured weight is used
as an offset so that the
displayed weight value
indicates the weight of the
sample only.
Temp
The heater is in stand-by
mode, and the experiment
has been terminated.
Unload
The TGA is unloading a
sample from the balance.
4–19
Technical Reference
4–20
TA INSTRUMENTS TGA 2050
CHAPTER 5: Maintenance and
Diagnostics
Overview .....................................................5-3
Routine Maintenance ..................................5-4
Inspection .............................................5-4
Cleaning the Instrument Keypad ..........5-4
Cleaning the Quartz
Furnace Tube ........................................5-4
Heat Exchanger ....................................5-7
Maintaining Heat
Exchanger Coolant ........................5-7
Draining and Refilling the
Water Reservoir .............................5-7
Replacing the Thermocouple ....................5-10
Diagnosing Power Problems .....................5-12
Fuses ...................................................5-12
Power Failures ....................................5-13
TGA 2050 Test Functions ........................5-14
The Confidence Test ..........................5-14
Replacement Parts ....................................5-16
TA INSTRUMENTS TGA 2050
5–1
Maintenance & Diagnostics
5–2
TA INSTRUMENTS TGA 2050
Overview
Overview
The procedures described in this section are the
customer’s responsibility. Any further maintenance should be performed by a representative
of TA Instruments or other qualified service
personnel.
!WARNING
TA INSTRUMENTS TGA 2050
Because of the high voltages in this instrument, untrained personnel must not attempt to test or repair any electrical
circuits..
5–3
Maintenance & Diagnostics
Routine Maintenance
Inspection
Examine the instrument periodically to keep it
free of dust, debris, and moisture. Keep the
furnace area clean. Any sample spillage of
residue should be removed before the next
experiment.
Cleaning the
Instrument Keypad
You can clean the TGA instrument keypad as
often as you like. The keypad is covered with a
silk-screen Mylar* overlay that is reasonably
water resistant but not waterproof or resistant to
strong solvents or abrasives.
A household liquid glass cleaner and paper
towel are best for cleaning the instrument
keypad. Wet the towel, not the keypad, with the
glass cleaner, and then wipe off the keypad.
Cleaning the
Quartz Furnace Tube
!WARNING
If the TGA is used to evaluate materials using
an oxygen purge, the furnace should be
cleaned routinely to prevent build-up of volatile
hydrocarbon residues that could combust.
!WARNING
Do not touch the furnace sample tube with
your bare fingers. Skin oils may cause
devitrification of the quartz glass, resulting
in severely reduced sample tube life.
5–4
TA INSTRUMENTS TGA 2050
Routine Maintenance
!WARNING
Do not insert metallic instruments inside the
sample tube to scrape or chip contaminants
from the sample tube as breakage may result .
Mylar is a registered trademark of the DuPont
Company.
*
To clean the furnace quartz sample tube, use the
following procedure:
!WARNING
Do not disturb the hangdown wire and
furnace thermocouple located directly
above the furnace when cleaning the furnace, as damage may result.
1. Press the FURNACE key to open the
furnace completely.
2. Remove any sample pans.
3. Remove the rubber cap located on the
underside of the furnace base.
4. Place a small cup under the furnace tube.
Rinse the furnace tube using a solvent (such
as alcohol) to remove debris. The solvent
will drain out of the bottom of the tube into
the cup.
5. Using a soft bristle brush (we recommend a
flexible bottle brush), gently slide the brush
up and down to clean out the inside of the
furnace tube, allowing the handle to bend
freely (see Figure 5.1 on the next page).
TA INSTRUMENTS TGA 2050
5–5
Maintenance & Diagnostics
Figure 5.1
Cleaning the
Inside of the
Funace Tube
6. Rinse the furnace tube with the solvent
again.
7. Replace the rubber cap on the quartz tube
stem when you have completed the cleaning
procedure.
8. Purge the system with nitrogen for one hour.
9. Heat the furnace to 900°C to remove any
remaining solvent.
5–6
TA INSTRUMENTS TGA 2050
Routine Maintenance
Heat Exchanger
The heat exchanger does not require any maintenance other than to maintain the level and
quality of the liquid coolant. If the level drops
too low, or the coolant becomes contaminated,
this could result in problems with your instrument.
!WARNING
Do not put any liquid other than distilled
water in the heat exchanger reservoir.
Maintaining Heat
Exchanger Coolant
You should check the level and condition of the
heat exchanger coolant periodically. We recommend routine checks every three to six months,
depending on use of the instrument.
Add distilled water to the reservoir, if necessary,
to keep the reservoir at least 2/3 full. If algae
growth is visible, drain the reservoir bottle, refill
it with distilled water, and add TA Instruments
TGA Conditioner, as described in the next
section.
Draining and Refilling
the Water Reservoir
Drain and refill the heat exchanger water
reservoir as follows:
1. Turn off the POWER switch and disconnect
the heat exchanger cable and water lines
from the instrument cabinet (see Chapter 2
for instructions).
TA INSTRUMENTS TGA 2050
5–7
Maintenance & Diagnostics
2. Unscrew and remove the water reservoir
cap.
3. Drain the coolant and flush out the system
as follows:
a.
Lift the heat exchanger and dump out
the contents of the water reservoir
bottle.
b. Fill the bottle to 2/3 full with distilled
water only and replace the cap.
c.
Reconnect the heat exchanger cable and
water lines to the instrument cabinet.
d. Turn on the POWER switch.
e.
Turn on the pump by activating Air
Cool (on the controller), and allow the
water to circulate for several minutes.
f.
Turn off the pump by deactivating Air
Cool, and check the clarity of the water
in the reservoir bottle.
g.
If the water clarity is still unacceptable,
disconnect the heat exchanger cable and
water lines from the instrument cabinet,
and repeat steps a through f.
h. Continue repeating this procedure until
you are satisfied with the clarity of the
water in the bottle after it has circulated.
4. Dispose of the water and fill the bottle with
TGA Conditioner (PN 952377.001) and
fresh distilled water as directed in Chapter 2
on pages 2-10 and 2-11.
5–8
TA INSTRUMENTS TGA 2050
Routine Maintenance
5. Turn on the pump again by activating Air
Cool, and circulate the water until the air
bubbles disappear from the water lines.
(You may see “Err 119” on the instrument
display until all the air has been removed.)
6. Replace and tighten the water reservoir cap.
TA INSTRUMENTS TGA 2050
5–9
Maintenance & Diagnostics
Replacing the
Thermocouple
1. Unload the sample pan and open the
instrument’s furnace.
2. Using the ball driver supplied in your TGA
accessory kit, loosen and remove the six
screws securing the balance chamber
faceplate to the instrument.
3. Take off the faceplate.
4. Push the thermocouple up from the bottom,
to feed it back into the balance chamber
(Figure 5.2).
Figure 5.2
Removing the
Thermocouple
5. Unplug the thermocouple from its connector
and remove the thermocouple from the
balance chamber.
6. Plug the new thermocouple carefully into
the connector.
5–10
TA INSTRUMENTS TGA 2050
Replacing the Thermocouple
7. Thread the new thermocouple down through
the hole next to the hang-down tube.
8. Thread the end of the thermocouple just
through the ceramic disk at the end of the
hang-down tube.
9. Load a sample pan to make sure that the end
of the thermocouple does not touch it
(Figure 5.3).
Figure 5.3
Checking Position
of Thermocouple
10. Make sure that the hang-down wire does not
touch the top of the thermocouple inside the
balance chamber.
11. Replace the balance chamber faceplate and
screws.
TA INSTRUMENTS TGA 2050
5–11
Maintenance & Diagnostics
Diagnosing
Power Problems
Fuses
The TGA contains internal fuses that are not
user serviceable. If any of the internal fuses
blow, a hazard may exist. Call your TA Instruments service representative.
The only fuses that you should service yourself
are the external fuses, located on the TGA’s rear
panel. Both are housed in safety-approved fuse
carriers, labeled F1 and F2 (Figure 5.4).
Always unplug the instrument before you
examine or replace the fuses.
E
FUSE
FUS
!WARNING
10 A
Figure 5.4
Fuse Locations
5–12
TA INSTRUMENTS TGA 2050
Diagnosing Power Problems
Fuse 1 is in the circuit between the main electrical input and the POWER switch. All power for
internal operations and instrument functions,
except heater power, passes through this fuse. If
this fuse blows, you will get no response from
the instrument when you attempt to turn it on.
Fuse 2 protects the heater coils in the furnace.
Because fuse 2 does not power the internal
logic, you may not know that this fuse is blown
until you try to heat a sample; the TGA passes
the confidence test with fuse 2 open.
Fuse 2 is always checked at the beginning of a
method. Power supplied by this circuit is
switched by a computer-controlled relay. If fuse
F2 is open at the start of a run, error 73 “No
heater power at startup” is displayed, then the
run is terminated.
Power Failures
A power failure caused by a temporary drop in
line voltage results in one of two responses by
the TGA instrument:
•
If the drop is fairly large and of long
duration (20 milliseconds or more), the
system will reset and go into its power-up
sequence when power resumes.
•
If the drop is small or of short duration, the
system may halt. The instrument will not
restart until it is reset. To reset, press the
Reset button on the TGA’s back panel.
The TGA is designed for a nominal line voltage
of 115 volts AC (+ 10%), 50 or 60 Hz. It should
not be operated outside this range. Low line
voltage may result in poor instrument operation;
high line voltage may damage the instrument.
TA INSTRUMENTS TGA 2050
5–13
Maintenance & Diagnostics
TGA 2050
Test Functions
The TGA 2050 has three levels of test and
diagnostic functions:
•
The confidence test that is run every time
the instrument is started.
•
Cycling test functions that continuously test
specific.
•
A manufacturing verifier test mode that
coordinates and logs the results of a
sequence of confidence test and drift runs.
These test functions are always present in the
instrument. They are designed to aid manufacturing and service in checking and repairing the
instrument.
The Confidence Test
The TGA 2050 confidence test is run each time
the instrument is turned on or reset. The confidence test checks most of the computer and
interface components in the system.
A standard 2050 instrument takes about 16
seconds to run the confidence test. During the
test the yellow ready light will flash several
times, indicating that the test is proceeding
normally. At the end of the test the ready light
will turn on and the instrument can be configured online.
5–14
TA INSTRUMENTS TGA 2050
TGA 2050 Test Functions
If the confidence test is completed without any
fatal errors detected, the ready light will turn on
and remain on steady and the instrument will
sound a beep. The instrument is now ready to
configure online to the instrument controller.
If a fatal problem is detected during the confidence test, the ready light will remain off or
continue to flash periodically. The instrument
cannot be configured online when fatal errors
are detected. Contact your TA Instruments
service representative for assistance.
If the confidence test detects a non-fatal problem
during startup, a confidence test error message
will be displayed on the controller when the
instrument is configured online. Non-fatal error
15, “CMOS RAM checksum error,” is displayed
immediately after new instrument software is
loaded into the 2050 instrument. Resetting the
instrument should clear this error. If error 15
persists, or if any other confidence test errors are
displayed, contact your TA Instruments service
representative for assistance.
TA INSTRUMENTS TGA 2050
5–15
Maintenance & Diagnostics
Replacement Parts
Table 5.1
TGA 2050 Parts List
Part Number
Description
952018.906
100 µL platinum sample
pan kit
100 µL ceramic sample
pan kit
Sample hang-down wire
Tare hang-down wire
Class M calibration
weight kit (100 mg and
1 gm)
Class M cal. wt. 100 mg
Class M cal wt. 1 gm
50 µL platinum sample
pan kit
250 µL ceramic sample
pan kit
500 µL ceramic sample
pan kit
Furnace assembly
Balance assembly
Tare tube
Motor drive PCB
Analog PCB
Sample thermocouple
assembly
Sample motor assembly
Furnace (down) sensor
Furnace (up) sensor
Sample position sensor
Furnace motor assembly
Aluminum sample pan
kit
(table continued)
952018.907
952040.901
952040.902
952011.906
269931.001
269931.002
952018.908
952018.909
952018.910
952350.901
952014.901
952017.001
952310.901
952060.901
952068.901
952080.901
952081.902
952081.903
952081.904
952082.901
952323.902
5–16
TA INSTRUMENTS TGA 2050
Replacement Parts
Table 5.1 (continued)
Part Number
Description
952384.901
TGA Temperature
Calibration Kit
Aluminum temperature
calibration standard
Calcium oxalate sample
Air purge valve
assembly
TGA 2050 keypad
assembly
Power supply assembly
Central processor PCB
Communications PCB
Triac drive PCB
Brass tweezers
Spatula, curved, 165
mm long
O-ring, furnace housing
to balance chamber
Balldriver, 0.050-inch
Balldriver, 7/64-inch
Class C calibration
weight kit
(1 mg to 500 mg)
TGA 2050 Cooling
Accessory
Heat exchanger fan/
assembly
Cooling Accessory
tubing
Cooling Accessory
water reservoir bottle
Cooling Accessory
pump assembly
952183.901
900905.901
990806.901
952410.001
993008.901
990850.901
993100.901
990870.901
259508.000
259509.000
269845.001
269920.002
269920.026
269930.001
952160.901
952160.903
952162.901
952166.901
952172.901
(table continued)
TA INSTRUMENTS TGA 2050
5–17
Maintenance & Diagnostics
Table 5.1 (continued)
Part Number
Description
952161.901
269932.001
952381.901
Flow switch assembly
Solid state relay
Upper furnace core kit,
EGA
Lower furnace core kit,
EGA
Furance tube replacement kit, EGA
952382.901
952357.901
5–18
TA INSTRUMENTS TGA 2050
Appendix A:
Ordering Information
For information or to
place an order, contact:
United States:
TA Instruments, Inc.
109 Lukens Drive
New Castle, DE 19720
Telephone: (302) 427-4000
Fax: (302) 427-4001
Overseas:
TA Instruments Ltd.
Europe House
Bilton Centre
Cleeve Road
Leatherhead, Surrey KT22 7UQ
England
Telephone: 44-1-372-360363
Fax: 44-1-372-360135
TA Instruments GmbH
Siemenstrasse 1
8755 Alzenau
Germany
Telephone: 49-6023-30044
Fax: 49-6023-30823
TA INSTRUMENTS TGA 2050
A–1
Appendix A
TA Instruments Benelux
Ottergemsesteenweg 461
B-9000 Gent
Belguim
Telephone: 32-9-220-79-89
Fax: 32-9-220-83-21
TA Instruments Japan
Iwata Building #5
28-11 Nishigotanda 2-Chome
Shinagawa-Ku, Tokyo 141
Japan
Telephone: 813-5434-2711
Fax: 813-5434-2770
For technical assistance or
service in the United States:
HOTLINE
For technical assistance with current or
potential thermal analysis applications,
please call the Thermal Analysis Helpdesk
at (302) 427-4070.
SERVICE
For instrument service and repairs,
please call (302) 427-4050.
ORDERING
To oder instruments and supplies,
please call (302) 427-4040.
A–2
TA INSTRUMENTS TGA 2050
Index
Index
Calib (status code)
A
accessories
setting up
calibration
temperature
weight 3-6
3-15
Air Cool (status code)
Air Cool option
4-15
3-18
B
balance
unpacking
3-5
cleaning
keypad 5-4
quartz furnace tube
5-4
Closing (status code)
4-15
Cold (status code)
2-21
4-15
Complete (status code)
balance arm 4-6
balance arm sensor
4-7
balance meter movement
balance purge
4-15
4-6
3-15
confidence test
5-14–5-16
coolant
heat exchanger
5-7
Cooling (status code)
binary address settings
2-16
binary address switches
2-16
4-15
4-16
E
electronics compartment
C
cabinet housing
4-11
cables
connecting 2-12
TGA Connector Panel
GPIB 2-14
power 2-20
TA INSTRUMENTS TGA 2050
2-13
4-11
Ending (status code)
4-16
Equilb (status code)
4-16
experiment
before starting 3-4
running 3-6
starting 3-20
stopping 3-21
I–1
Index
F
H
fittings
cooling gas 2-19
purge 2-17
hang-down wire assemblies 4-7
flow rates
hang-down wires
aligning 2-27
installing 2-23, 2-24
3-17
forced start 3-20
Heat Exchanger 4-13
cables 2-12
components 4-13
filling 2-10
maintenance 5-7
maintaining coolant level
water lines 2-12
water reservoir 5-7
FURNACE key 1-7, 1-9
furnace 4-9
air cool 3-18
supply valve
furnace base
3-18
4-10
Heat Exchanger Water Line Connections 2-14
furnace tube
cleaning 5-4
Heating (status code)
fuses 5-12
location 5-12
Hot (status code)
gas 3-16
purge 3-15
using the TGA in an oxygen-free
environment 3-23
GPIB
cable 2-14
I–2
4-16
Holding (status code) 4-16
G
Gas Switching Accessory
using 3-18
5-7
1-10
4-16
I
Initial (status code)
Inspection
4-17
2-8
installation
hang-down wires 2-23
instrument
keypad 1-7, 1-8
setup 3-24
shutting down 2-33
TA INSTRUMENTS TGA 2050
Index
Iso (status code)
4-17
P
J
Jumping (status code)
4-17
parts
K
keypad 1-7, 1-8
automatic functions
cleaning 5-4
1-9
Location
choosing
5-16
power fuse
1-7
4-17
No Power (status code)
4-17
4-3
O
Opening (status code)
5-12
2-32
POWER Light
1-9, 2-32
purge fittings
4-11
purge gas 2-18, 3-15
system 3-23
2-9
N
null position
parts list
power
cable 2-20
diagnosing problems
failures 5-13
switch 2-20
lines
connecting 2-12
cooling gas 2-19
purge 2-17
Load (status code)
5-16
photodiodes 4-3
L
LOAD key
pans
selecting 3-7
taring 3-8
type 3-7
R
Ready (status code)
4-17
Reject (status code)
4-18
Repeat (status code)
4-18
4-17
TA INSTRUMENTS TGA 2050
I–3
Index
STOP key
S
sample
loading 3-10
pans
ceramic 3-7
ceramic pans 3-7
platinum pans 3-7
selecting 3-7
taring 3-8
preparing 3-7
unloading 3-22
sample pans
T
TARE key
tare pan
4-18
1-11
Stand by (status code)
start
forced
3-20
starting
instrument 2-32
status codes
I–4
4-18
1-7, 1-9
Started (status code)
4-15
4-7
Temp (status code) 4-19
shutting down
instrument 2-33
START key
4-19
taring
automatic 3-9
manual 3-9
pans 3-8
sample platform 1-4
adjusting 2-31
description 1-4
specifications
1-7
Tare (status code)
4-7
Set Up (status code)
1-8
4-18
TGA 2050
accessories
other accessories 1-10
balance 4-6
cabinet 4-11
cooling gas fitting 4-12
calibration 3-5
components 1-4, 4-5
balance 1-4, 4-5
cabinet 1-4
furnace 1-4, 4-5
heat exchanger 1-4, 4-5
sample loading assembly 4-5
confidence test 5-14–5-16
connecting cables 2-12
description 1-3, 1-6, 4-3
furnace
sample tube 4-9
fuses 5-12
heat exchanger 4-13
inspecting 2-8
inspection 5-4
TA INSTRUMENTS TGA 2050
Index
TGA 2050 (cont’d)
installing 2-7
keypad 1-6, 1-7, 1-8
location of 2-9
maintenance 5-4
parts list 5-16
power failures 5-13
power problems 5-12
purge fittings 4-11
repacking 2-6
replacement parts 5-16
replacing thermocouple 5-10
running an experiment 3-6
sample loading assembly 4-8
sample tube 4-9
setting up an experiment 3-14
shutting down 2-33
specifications 1-11
starting 2-32
test functions 5-14
theory of operation 4-14
thermocouple
position of 5-11
removing 5-11
unpacking 2-3
installing mounting feet 2-5
using in an oxygen-free environment 3-23
weight ranges 4-3
Theory of Operation
U
UNLOAD key
1-7
Unload (status code)
4-19
unpacking
balance 2-21
W
wires
hang-down 2-23
aligning 2-27
4-14
thermocouple 4-10
adjusting 3-11
removing 5-10
replacing 5-10
TA INSTRUMENTS TGA 2050
I–5
Index
I–6
TA INSTRUMENTS TGA 2050
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