TA Instruments TGA 2050 Operator'S Manual Download Page 65

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TA I

NSTRUMENTS

TGA 2050

3–5

Calibrating the TGA

The TGA 2050 requires two kinds of calibra-

tion: temperature calibration and weight cali-

bration. 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 compar-

ing the observed value with the standard litera-

ture 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

Calibrating the TGA

Summary of Contents for TGA 2050

Page 1: ...TA INSTRUMENTS TGA 2050 I 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 Thermal Analysis Rheology ...

Page 2: ...tion is not a license to operate under or a recommendation to infringe upon any process patents TA Instruments Operating Software and Mod ule Data Analysis and Utility Software and their associated manuals are proprietary and copyrighted by TA Instruments Inc Purchas ers are granted a nonexclusive nontransferable license to use these software programs on the module and controller with which they w...

Page 3: ...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 ...

Page 4: ... 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 ...

Page 5: ...electing 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 ...

Page 6: ...cription 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 ...

Page 7: ...anger 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 ...

Page 8: ...ical instructions A NOTE highlights important information about equipment or procedures A CAUTION emphasizes a procedure that may damage equipment or cause loss of data if not followed correctly A WARNING indicates a procedure that may be hazardous to the operator or to the environment if not followed correctly NOTE WARNING t CAUTION ...

Page 9: ...NTS TGA 2050 IX 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 ...

Page 10: ... only by TA Instruments or other qualified service personnel After transport or storage in humid condi tions 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...

Page 11: ...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 han dling RCF insulation Thermal Safety After running an experiment allow the open furnace and thermocouple to cool down before you touch them During a ...

Page 12: ...ical information on the procedures described in Chapter 5 and explains principles of TGA opera tion 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 assis tance ...

Page 13: ...APTER 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 ...

Page 14: ...Introducing the TGA 2050 1 2 TA INSTRUMENTS TGA 2050 ...

Page 15: ...hibits a weight change and to detect phase changes due to decomposition oxidation or dehydration This information helps the scien tist or engineer identify the percent weight change and correlate chemical structure pro cessing 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...

Page 16: ...illustrated in Figure 1 2 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 ...

Page 17: ...TA INSTRUMENTS TGA 2050 1 5 Figure 1 2 TGA 2050 Components Introduction Cabinet Balance Heat Exchanger Furnace Sample Loading Assembly ...

Page 18: ...ations at the instru ment automatic balance tare furnace elevator sample loading platform and experiment start and stop functions Figure 1 3 TGA 2050 Keypad Table 1 1 explains the functions of the instru ment keys Experiment information and instrument constants are entered from the controller keyboard not the instrument keypad NOTE Start Stop ...

Page 19: ...ght 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 movem...

Page 20: ...his 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 method end state the STOP key will halt any activity air cool all mechanical motion etc ...

Page 21: ...ally 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 The 2050 Instrument ...

Page 22: ... 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 manu facturers including vacuum FTIR gas chro matographs mass spectrometers and evolved gas analyzers Consult the appropriate local instrument manufacturer for further information ...

Page 23: ...ions Table 1 2 TGA 2050 Specifications Temperature range 25o C to 1000o C Thermocouple Platinel II Heating rate 0 1 to 50 C min Operating line voltage 115 volts 50 60 Hz Energyconsumption 1 5 kVA Platinel II is a registered trademark of EngelhardIndustries ...

Page 24: ...ement2 Resolution 0 2 µg Accuracy 0 1 Ranges 100 mg range 10 mg to 100 mg 1000 mg range 100 mg to 1000 mg 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 mecha nism is sensitive to changes in the surrounding room temperature For opt...

Page 25: ...ntinued Furnace Atmosphere Purge gases Helium nitrogen oxygen air argon3 Purge rate Up to 100 cc min 3 Do not use hydrogen or any other explosive gas in the TGA 2050 Oxy gen may be used How ever the furnace must be kept clean of hydrocar bons to prevent combus tion WARNING ...

Page 26: ...Introducing the TGA 2050 1 14 TA INSTRUMENTS TGA 2050 ...

Page 27: ... 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 ...

Page 28: ...Installing the TGA 2050 TA INSTRUMENTS TGA 2050 2 2 Starting the 2050 2 32 Shutting Down the Instrument 2 33 ...

Page 29: ...d 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 Have an assistant help you unpack this unit Do not attempt to do this alone Figure 2 1 Shipping Boxes Unpacking Repacking the 2050 NOTE WARNING ...

Page 30: ...t 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 ...

Page 31: ...ck 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 4 inch 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...

Page 32: ...ng 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 ...

Page 33: ... 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 Representat...

Page 34: ...tainer 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 ...

Page 35: ...tions in Chapter 1 for the instrument dimen sions 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 dusty environments exposu...

Page 36: ... 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...

Page 37: ...inner rim see Figure 2 5 with distilled water 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 Do not put any water other than distilled water in the heat exchanger reservoir 3 Replace and tighten the water reservoir cap Installing the Instrument Fill to bottle s inner rim NOTE t t t t t CAUTION ...

Page 38: ...s to outlets Tighten the thumbscrews on all computer cables Whenever plugging or unplugging power cords handle them by the plugs not by the cords 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...

Page 39: ...e 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 RE TURN on the heat exchanger Figure 2 7 on the next page illustrates the correct water line connections for the TGA and h...

Page 40: ...he 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 cab...

Page 41: ...connec tor panel to set the desired address Table 2 1 Figure 2 8 shows a instrument address of 7 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 ...

Page 42: ... 2050 Table 2 1 Binary Address Settings Switch Pattern Address 1 2 3 4 5 1 0 0 0 0 1 2 0 0 0 1 0 3 0 0 0 1 1 4 0 0 1 0 0 5 0 0 1 0 1 6 0 0 1 1 0 7 0 0 1 1 1 8 0 1 0 0 0 9 0 1 0 0 1 0 OFF 1 ON Figure 2 8 Binary Address Switches ADDRESS 1 2 3 4 5 O N ...

Page 43: ... 2 17 Purge Lines 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 Figure 2 9 TGA PURGE Fittings WARNING Installing the Instrument FU SE FUS E ...

Page 44: ...nd 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 combus tion 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 requiremen...

Page 45: ...rked with a 120 psig maximum warning label Figure 2 10 Figure 2 10 TGA 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 Nitrogen may also be used as a cooling gas Installing the Instrument CoolingGasFitting NOTE 10 A ...

Page 46: ...the OFF position Figure 2 11 TGA POWER Switch 2 Plug the power cable into the TGA 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 F U S E FU SE Power Switch t t t t t CAUTION 10 A ...

Page 47: ...he 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 Figure 2 12 Interior of Balance Chamber Before Unpacking Unpacking the Balance t CAUTION Balance Cover Sample Side Ta...

Page 48: ...3 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 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 Foam Insert ...

Page 49: ...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 hang down 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...

Page 50: ...o 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 ha...

Page 51: ...TA INSTRUMENTS TGA 2050 2 25 Figure 2 15 Installing the Tare Hang Down Wire Installing the Hang Down Wires ...

Page 52: ...nce 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 ...

Page 53: ...actory 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 b...

Page 54: ...f the wire is not roughly centered inside the hang down tube turn the balance adjust ment 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 Figure 2 16 Location of Balance Adjustment Screw Topof Hang Down Tube Balance Adjustment Scre...

Page 55: ...of the sample pan within the furnace It should hang freely roughly centered and should not be touch ing the sides of the furnace or the hang down tube Figure 2 17 3 If the sample pan is not centered and hang ing 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 ...

Page 56: ...e 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 Furnace Housing Hang Down Tube Sample Pan ...

Page 57: ...ple hang down wire fails to pick up a sample pan during an automatic loading proce dure 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 ...

Page 58: ...ct 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 fu...

Page 59: ...ntroller 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 dis couraged 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 ...

Page 60: ...Installing the TGA 2050 2 34 TA INSTRUMENTS TGA 2050 ...

Page 61: ...ng 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 ...

Page 62: ...Running Experiments 3 2 TA INSTRUMENTS TGA 2050 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 ...

Page 63: ...ermal 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 docu...

Page 64: ...roperly Make sure you have 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 ...

Page 65: ...nd documentation for further information Temperature Calibration Temperature calibration involves analyzing a material for its Curie Temperature and compar ing the observed value with the standard litera ture 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 ther...

Page 66: ...ental Procedure All of your TGA experiments will have the following general outline 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 controlle...

Page 67: ...s 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 abov...

Page 68: ...e 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 ...

Page 69: ...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 prot...

Page 70: ...ion 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 Always use brass tweezers to handle the sample pans Manually loading the sample pan onto the hang down wire may damage the balance mechanism Figure 3 2 Sample Pan Ready to Load NOTE t CAUTION ...

Page 71: ...mocouple at the edge of the sample pan rather than in the middle for best results Figure 3 3 The position of the thermocouple should be the same as it was during temperature calibration Figure 3 3 Adjusting the Thermocouple NOTE Sample Hook Thermocouple shouldbe about2mm fromthepan surface SamplePan Thermocouple Running an Experiment ...

Page 72: ...Running Experiments 3 12 TA INSTRUMENTS TGA 2050 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 ...

Page 73: ...TA INSTRUMENTS TGA 2050 3 13 Figure 3 5 Furnace in Fully Closed Position Running an Experiment ...

Page 74: ...ent 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 ...

Page 75: ... with other acces sories such as vacuum FTIR gas chromato graphs mass spectrometers and evolved gas analyzers Consult the appropriate local instru ment 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 cham...

Page 76: ...igure 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 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...

Page 77: ...ss 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 ...

Page 78: ...lso be used as a cooling gas 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 expe...

Page 79: ...itching 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 Running an Experiment ...

Page 80: ...seful for samples that loose a significant amount of weight during the set up period i e samples with volatile sol vents 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 Once the experiment is sta...

Page 81: ...on 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 The Heat Exchanger will continue to run as long as the Air Cool option is activated or until the indi cated temperature is below 50o C The REJECT function discards all experim...

Page 82: ...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 ...

Page 83: ...ty 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 ...

Page 84: ...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 sy...

Page 85: ...TGA 2050 4 1 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 ...

Page 86: ...Technical Reference TA INSTRUMENTS TGA 2050 4 2 ...

Page 87: ...y 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 rang...

Page 88: ...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 mea sured by the thermocouple located above the sample This enables the controller to program and maintain the sample environment at your selected rate ...

Page 89: ...e TGA system provides precise measurement of the sample weight The sample loading assem bly 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 Description of the TGA 2050 Heat Exchanger Balance Chamber Power Light Ready L...

Page 90: ...ple pan and the 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 alumi num 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 BalanceArm Sensor BalanceMeter Movement TarePan Balance Arm Sample Pan...

Page 91: ... 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 ...

Page 92: ... loading assembly Figure 4 3 is a platform that pivots the sample pan to the furnace area where the pan engages the hang down 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 ...

Page 93: ... 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 i...

Page 94: ...esistance 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 o...

Page 95: ...ists 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 f...

Page 96: ...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 Figure 4 6 Rear Panel FU SE FUS E ...

Page 97: ... 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 tempera ture 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 Figure 4 7 Heat Exchanger Description of the TGA 2050 ...

Page 98: ... function of temperature and time It is used to characterize any material that exhibits weight loss or phase changes as a result of decomposition dehydra tion 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 tempera ture is kept constant ...

Page 99: ... 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 thermo couple signal Complete The thermal method has finished table continued ...

Page 100: ...ilb 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 con tinue 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 ...

Page 101: ...e 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 equili brated at the initial temperature and is ready to begin the next segment Use the Start function to ...

Page 102: ...ntrol segments Set Up The system is loading the sample closing the furnace and letting the weight stabilize before beginning the first seg ment Stand by The method and method end operations are com plete Started The TGA is still setting up to start the experiment see Set Up above but the initial weight has been measured and data col lection has begun The thermal method will start when the normal s...

Page 103: ...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 ...

Page 104: ...Technical Reference TA INSTRUMENTS TGA 2050 4 20 ...

Page 105: ...nstrument 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 ...

Page 106: ...TA INSTRUMENTS TGA 2050 Maintenance Diagnostics 5 2 ...

Page 107: ...stomer s responsibility Any further mainte nance should be performed by a representative of TA Instruments or other qualified service personnel Because of the high voltages in this instru ment untrained personnel must not at tempt to test or repair any electrical circuits WARNING Overview ...

Page 108: ...er 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 If the TGA is used to evaluate materials using an oxygen purge the furnace should be cleaned routinely to prevent bu...

Page 109: ...ce 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 fl...

Page 110: ... 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 ...

Page 111: ...t exchanger coolant periodically We recom mend 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 Wat...

Page 112: ...mp 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...

Page 113: ...ain 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 Routine Maintenance ...

Page 114: ...oosen 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...

Page 115: ...mic 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 Replacing the Thermocouple ...

Page 116: ... blow a hazard may exist Call your TA Instru ments 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 Figure 5 4 Fuse Locations WARNING F U S E FU SE 10 A ...

Page 117: ...omputer 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 w...

Page 118: ... are always present in the instrument They are designed to aid manufac turing 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 confi dence 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 D...

Page 119: ... 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 205...

Page 120: ... M cal wt 100 mg 269931 002 Class M cal wt 1 gm 952018 908 50 µL platinum sample pan kit 952018 909 250 µL ceramic sample pan kit 952018 910 500 µL ceramic sample pan kit 952350 901 Furnace assembly 952014 901 Balance assembly 952017 001 Tare tube 952310 901 Motor drive PCB 952060 901 Analog PCB 952068 901 Sample thermocouple assembly 952080 901 Sample motor assembly 952081 902 Furnace down sensor...

Page 121: ...CB 993100 901 Communications PCB 990870 901 Triac drive PCB 259508 000 Brass tweezers 259509 000 Spatula curved 165 mm long 269845 001 O ring furnace housing to balance chamber 269920 002 Balldriver 0 050 inch 269920 026 Balldriver 7 64 inch 269930 001 Class C calibration weight kit 1 mg to 500 mg 952160 901 TGA 2050 Cooling Accessory 952160 903 Heat exchanger fan assembly 952162 901 Cooling Acces...

Page 122: ...agnostics 5 18 Table 5 1 continued Part Number Description 952161 901 Flow switch assembly 269932 001 Solid state relay 952381 901 Upper furnace core kit EGA 952382 901 Lower furnace core kit EGA 952357 901 Furance tube replace ment kit EGA ...

Page 123: ...nts 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 ...

Page 124: ...me 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 ...

Page 125: ...net housing 4 11 cables connecting 2 12 TGA Connector Panel 2 13 GPIB 2 14 power 2 20 Calib status code 4 15 calibration temperature 3 5 weight 3 6 cleaning keypad 5 4 quartz furnace tube 5 4 Closing status code 4 15 Cold status code 4 15 Complete status code 4 15 confidence test 5 14 5 16 coolant heat exchanger 5 7 Cooling status code 4 16 E electronics compartment 4 11 Ending status code 4 16 Eq...

Page 126: ...ching Accessory 1 10 using 3 18 GPIB cable 2 14 H hang down wire assemblies 4 7 hang down wires aligning 2 27 installing 2 23 2 24 Heat Exchanger 4 13 cables 2 12 components 4 13 filling 2 10 maintenance 5 7 maintaining coolant level 5 7 water lines 2 12 water reservoir 5 7 Heat Exchanger Water Line Connec tions 2 14 Heating status code 4 16 Holding status code 4 16 Hot status code 4 16 I Initial ...

Page 127: ... 9 2 32 purge fittings 4 11 purge gas 2 18 3 15 system 3 23 R Ready status code 4 17 Reject status code 4 18 Repeat status code 4 18 Iso status code 4 17 J Jumping status code 4 17 K keypad 1 7 1 8 automatic functions 1 9 cleaning 5 4 L lines connecting 2 12 cooling gas 2 19 purge 2 17 LOAD key 1 7 Load status code 4 17 Location choosing 2 9 N No Power status code 4 17 null position 4 3 O Opening ...

Page 128: ...ted status code 4 18 starting instrument 2 32 status codes 4 15 STOP key 1 8 T TARE key 1 7 Tare status code 4 19 tare pan 4 7 taring automatic 3 9 manual 3 9 pans 3 8 Temp status code 4 19 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...

Page 129: ...ing 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 environ ment 3 23 weight ranges 4 3 Theory of Operation 4 14 thermocouple 4 10 adjusting 3 11 removing 5 10 replacing 5 10 U UNL...

Page 130: ...Index TA INSTRUMENTS TGA 2050 I 6 ...

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