dsc 131 manual

G/DSC131-1A

DSC 131

COMMISSIONING UTILIZATIONS

DSC 131 - Commissioning/Utilizations

Contents i

CONTENTS

♦ CONTENTS ................................................................................................................ I

♦ REVISIONS TABLE.............................................. .................................................. I

♦ WARNING TO USERS .................................................................................................1

♦ CHAPTER 1 – COMMISSIONING...................................................................................2

1. PRESENTATION ...........................................................................................................................2 2. 2. INSTALLATION .........................................................................................................................3

2.1. Location .......................................................................................................................................4 2.2. Dimensions and weight................................................................................................................4 2.3. Electrical circuit ...........................................................................................................................4

3. ELECTRICAL AND COMPUTER CONNECTIONS .................................................................................5 3.1. Electrical connections ..................................................................................................................5 3.2. Computer connections .................................................................................................................5

4. FLUID CONNECTIONS ...................................................................................................................6 4.1. Sweeping gas circuit ....................................................................................................................6 4.2. Cooling circuit .............................................................................................................................8

4.2.1. Air cooling........................................................................................................................8 4.2.2. Cooling accelerator...........................................................................................................9 4.2.3. Cooling with a cryogenic plunging device .....................................................................10

4.2.3.1. Device ___________________________________________________________________10 4.2.3.2. First commissioning _________________________________________________________11 4.2.3.3. Utilization_________________________________________________________________11 4.2.3.4. Stopping the device _________________________________________________________12

4.2.4. Liquid nitrogen cooling device.......................................................................................12 5. COMMISSIONING OF THE CALORIMETRIC TRANSDUCER ................................................................ 13

5.1. Presentation................................................................................................................................13 5.2. Commissioning ..........................................................................................................................14

6. TECHNICAL CHARACTERISTICS .................................................................................................. 15 6.1. DSC 131.....................................................................................................................................15 6.2. Cryogenic device .......................................................................................................................16 6.3. Materials in contact with the gas ...............................................................................................16 6.4. Conforming to standards............................................................................................................16

♦ CHAPTER 2 - UTILIZATIONS .....................................................................................20

1. SELECTING THE CRUCIBLE ........................................................................................................ 20 1.1. Low-volume aluminum crucible................................................................................................21

1.1.1. Description .....................................................................................................................21 1.1.2. Crimping.........................................................................................................................21 1.1.3. Utilization .......................................................................................................................22

1.2. Medium-volume aluminum crucible..........................................................................................23 1.2.1. Description .....................................................................................................................23


Contents ii

1.2.2. Crimping.........................................................................................................................23 1.2.3. Utilization .......................................................................................................................26

1.3. High Pressure crucible 500 bars 600°C S60/58186..................................................................27 1.3.1. Description .....................................................................................................................27 1.3.2. Crimping.........................................................................................................................28 1.3.3. Utilization .......................................................................................................................30

1.3.3.1. Instructions for use__________________________________________________________30 2. PREPARING THE EXPERIMENT.................................................................................................... 31

2.1. Weighing a sample.....................................................................................................................31 2.2. Placing crucibles in the DSC .....................................................................................................32 2.3. Selecting the sweeping gas ........................................................................................................33 2.4. Entering experimental conditions ..............................................................................................33

2.4.1. PID actions .....................................................................................................................34 2.4.2. Safety temperature ..........................................................................................................34 2.4.3. Control valve and fan .....................................................................................................34 2.4.4. Scanning and sequencing ...............................................................................................35

2.4.4.1. Simple cycle _______________________________________________________________36 2.4.4.2. Staged cycle _______________________________________________________________37 2.5. Making use of the test ................................................................................................................39

2.5.1. Thermogramme ..............................................................................................................39 2.5.2. Determining transformation temperatures (or times) .....................................................40

2.5.2.1. Endothermic transformation___________________________________________________40 2.5.2.2. Exothermic transformation____________________________________________________41 2.5.2.3. Glass transition_____________________________________________________________42

2.5.3. Temperature correction...................................................................................................43 2.5.3.1. Standard materials __________________________________________________________44 2.5.3.2. Experimenting _____________________________________________________________44 2.5.3.3. Temperature correction for a fixed scanning rate___________________________________46 2.5.3.4. Temperature correction for various scanning rates _________________________________47 2.6. Energy calibration......................................................................................................................48

2.6.1. Measuring the fusion heat of a pure substance...............................................................48 2.6.2. Standard materials ..........................................................................................................49 2.6.3. Experimenting ................................................................................................................50 2.6.4. Calibration with a single standard ..................................................................................50 2.6.5. Calibration with various standards .................................................................................51

♦ APPENDIX A...........................................................................................................52

♦ APPENDIX B...........................................................................................................53

♦ APPENDIX C...........................................................................................................54

♦ ANNEX D .............................................................................................................54


REVISIONS TABLE

REVISIONS TABLE

G 07/07/06 Add electrical scheme G/DSC131-1A J. DENIS C. MATHONAT

F 12/06/06 General corrections F/DSC131-1A T. THIMON /

A.FOUILLAT

C. MATHONAT

E 01/06/06 New HP crucibles E/DSC131-1A C. MATHONAT

D 21/06/05 Corrections D/DSC131-1A C.MATHONAT C. CARTET C. MATHONAT

C 23/02/05 Max N2Temperature C/DSC131-1A C. MATHONAT G.BOURDIN C. MATHONAT

B 28/07/04 Modification of tight

crucible pressure use B/DSC131-1A S. BENOIT C.MATHONAT C. MATHONAT

A 26/09/03 P35 corrosive and

reducing gases use

caution adding

A/DSC131-1A J. PICOCHE C.MATHONAT/

S.MARTINELLO C.MATHONAT

C 17/02/03 MODIFICATIONS C/DSC131A P. FOURNIER C. CARTET C. MATHONAT

B 21/10/99 LAY OUT B/DSC131A J.L. DAUDON K. DAVAT JL. DAUDON

REV DATE REVISION PURPOSE BOOKLET

REF

REQUIRED BY DONE BY APPROVED BY


Warning to users 1 G/DSC131-1A – 07/07/06

WARNING TO USERS Operating the instrument requires scientific and technical skill providing for

compliance with all the laws of chemistry and physics.

The specifications and applications of our products are always likely to be

modified. SETARAM will respond to any foreseeable damage directly linked to faults in its instruments, within the limits of the obligatory provisions in the law

applying to the victim's action.

SETARAM is in no way liable for the damage resulting from experiments carried out with its instruments. Non-compliance with the advice and instructions

contained in the commissioning or operating booklets will always be grounds for

excluding liability, in particular, in case of instrument’s alterations not expressly

approved by SETARAM .

Before commissioning the instrument, carefully read the instructions and fully

comply with every point. Commissioning of various instruments require strict

compliance with the directions and warnings contained in the various booklets.

To use peripheral instruments together with our apparatus (like for instance,

computer, thermostated bath, pump...), report to specific user’s manuals, delivered

with each peripheral in order to guarantee a good working order as well as a good

safety level of those equipments for our applications.

The instrument does not have a locking system preventing the access to the

transducer whereas it could be able to stay at a high temperature. It is necessary

to check this temperature thanks to the window Direct Programming (report to the Setsoft booklet) before opening the instrument.

Safety recommendations:

Carry the instrument with carefulness.

Think that vibrations or a shock may cause damages inside the instrument.

Read carefully safety labels.

Do not remove any label!

Do not switch on the instrument in case it is damaged.

Before getting the instrument repaired, unplug it.

Do not switch on an instrument on which feed cable is damaged.

Once the instrument has been correctly installed, the customer will ensure that

those operating it have the technical and scientific skills. He will make sure that


Warning to users 2 G/DSC131-1A – 07/07/06

the products worked upon, as well as the experimenting conditions, are not likely

to cause damage resulting from non-compliance with the laws of physics and

chemistry. The customer will also ensure, under his public liability, that the

instrument and its connections are not accessible to any operating or maintenance

staff unaware of the operating instructions.

Any use not corresponding exactly to the instrument's general specifications will

require initial contact being made with SETARAM .

The instruction leaflet enumerates other recommendations,

indicated through a triangle with an exclamation mark in it. Read

and follow carefully those recommendations! If you DO NOT, it

could generate serious consequences such as a breakdown,

material damages as well as hurting people badly and even kill

them.

Indicates a high temperature area.

Indicates an electric danger.

Indicates a low temperature area.

Indicates a risk of catching or crushing one’s hand.

CHAPTER 1 – COMMISSIONING

1. Presentation

Due to its experience in the technology of DSC analyzers, SETARAM has developed a new analyzer called DSC 131.

Performances such as selectivity, sensitivity, rapidity are the result of the original

measuring principle used for the construction and operation of the DSC 131’s

transducer.

This booklet shows the DSC 131 analyzer distinguished by the following features:


Commissioning 3 G/DSC131-1A – 07/07/06

• a single structure including the transducer, its cooling system and microprocessor-controlled controller.

• a multitask software package enabling piloting other modules (for instance modules from the labsysTM line).

• a varied range of crucibles available for the various types of experiment.

FIGURE 1: DSC 131

The DSC 131 instrument is designed for ease of operation while offering

robustness and high performance.

This instrument is appropriate for work in laboratories carrying out research and

quality control, in universities and schools, providing that the instructions given at

the beginning of this booklet are followed.

This instruction booklet -which contains various parts (commissioning,

utilization, maintenance, practical applications)- is especially intended for

commissioning the instrument and for describing the main operating modes.

Software operations will be dealt with separately.

2. 2. Installation

When a DSC 131 instrument has been ordered, the various parts

of the instrument are carefully checked and tested before

shipment.

Upon receipt of the equipment, carefully check the various parts

for their condition. Should any be damaged, make the customary

claim against the transport operator.

Check that the material delivered is the one you ordered.



2.1. Location

The DSC 131 instrument is best installed on a stable table, such as a laboratory

bench.

The instrument must be sheltered from draughts, and, if possible from the sun’s

rays, especially the rear panel (thermocouple measurement housing and pre-

amplifier housing).

2.2. Dimensions and weight

The DSC 131 instrument has a compact structure including various elements: a

detector, a furnace and a controller.

A series cable connects the instrument to the computer, itself combined with a

printer-plotter.

Weight : 23 kg/≈56 lb

FIGURE 2: DIMENSIONS OF THE DSC 131

The unit should be carried by two persons and held at the bottom

of the structure.

2.3. Electrical circuit

The instrument is to be used at 230 Volts.

If any other voltage is required, a transformer to be fitted between

the instrument and the mains power point is to be added.



Do plug the instrument ONLY in a ground connection.

3. Electrical and computer connections

3.1. Electrical connections

A single supply cable on the rear panel is to be connected to the mains 230 V /2A

with ground connection (figure 3).

Refer to the Maintenance chapter in the Practical Work/Maintenance booklet for any modification on cards.

Port série

Serial port

Disjonteur

Circuit breaker

Secteur

Main

FIGURE 3: ELECTRICAL CONNECTIONS

3.2. Computer connections

Note As the computer models undergo frequent changes, instructions for

connecting the computer itself are subject to modifications. Information about

connections for a COMPAQ computer is given in the present chapter.

Therefore, it is necessary to refer to the computer’s operating

booklet.

The instrument and more precisely the CS332 controller, is linked to the computer

via an RS232-series cable, containing 9-pin connectors at both ends.

Connections are as shown on the figure hereafter:



FIGURE 4: COMPUTER CONNECTIONS

• series-cable between (1) (serial port controller) and (2) (computer) • screen cable between (3) (central unit) and (4) (screen) • printer/plotter cable between (5) (central unit) and (6) (printer/plotter) • connection cable for the mouse on (7) • connection cable for the keyboard on (8) • connection to the mains for the central unit on (9) • connection to the mains for the screen on (10)

If the connector on the computer’s series cable contains more than

9 pins, an adaptor -which is not supplied- is required.

4. Fluid connections

4.1. Sweeping gas circuit

The sweeping gas circuit aims at:

1. preventing the crucible and the sample from oxidizing, 2. preventing the DSC transducer from oxidizing when the temperature is higher than 500°C in isothermal condition or 600°C in scanning condition (up to

5°C.min-1).

3. imposing a gas different from the air.

Two possibilities are available according to the option:

1. A single sweeping gas linked to the inlet 1 on the rear panel. A regulation valve is used to set the rate.



2. Automatic gas switching: two inlets identified as inlet 1 and inlet 2 are linked to an electrovalve piloted via the software. A regulation valve to be found on

each inlet is used to set a rate. This option allows either two various gases to be

switched or a single gas to have two different rates (rapid purging to push the

air out before starting an experiment).

For gas connection, see Figure 5 hereafter:

Vanne de réglage

Control valve

Entrée 1

Inlet 1

Sortie

Outlet

Entrée 2

Inlet 2

Gaz

Gas

FIGURE 5: GAS CONNECTIONS

A gauge pressure with a pressure-relief valve is fixed on the gas bottle. Link the

gauge pressure outlet to the instrument inlet located on the rear panel. Reduce to a

pressure of about 1.5 bars.

Outlet of the experimenting chamber is connected to outlet on the instrument’s

rear panel.

Inlet and outlet on the instrument’s rear panel have unions (refer to Chapter 2 - 7 -

Gas connections on the rear panel in the Practical work/Maintenance booklet for tightening the connections.)

The loss of mass is pre-adjusted in our workshop. A flowmeter must be used at

the instrument outlet to check or adjust the rate to the experiment. Rates of a few

liters per hour are recommended.

WARNING Fully tighten the unions around the pressure gauge to prevent any leak, and the bottle from emptying rapidly.

To check the fluid-tightness:

• Close the experimenting chamber with a stopper on the gas outlet.



• Open the gas supply bottle and reduce the pressure to about 1.5 bars.

• Open the pressure-relief valve.

• Use soapy water or any other means of detecting leaks to test the various

connections.

Should there be a leak, further check the flexible hoses, and especially check that

the ends are finless.

WARNING The gas used or released by a sample after a reaction must be chemically compatible with the various elements of the gas circuit (refer to the

chapter 1-6 in this booklet).

If a gas released by a sample is susceptible to be combustible or

toxic, Outlet, in the rear face of the instrument, must be linked to

a device insuring the safety of persons or goods.

4.2. Cooling circuit

4.2.1. Air cooling

The transducer is surrounded by a pipe (1) guiding the cooling air. A fan placed at

the far end of the pipe ensures the circulation of cooling air (see the figure

hereafter). The fan is controlled by the software on the window ‘’direct

programming’’ or ‘’sequences’’.

Erreur ! Des objets ne peuvent pas être créés à partir des codes de champs de mise en forme.

FIGURE 6: AIR COOLING

Cooling the transducer is done via the pipe and provides for various operations:

• Cooling the convector to protect the users. • Cooling the furnace support and protection of their various respective seals. • Cooling the instrument rapidly when from a high temperature (after heating process) down to ambient.

The fan must always be On, unless in sub ambient use.

WARNING A safety thermostat cuts the power when the temperature of the furnace base is higher than 100°C.



4.2.2. Cooling accelerator

WARNING This device is designed to improve the thermal coupling between the transducer and the heater and therefore natural cooling is increased at a maximum

speed.

Temperature/ °C

50100150200250300350400450500

dTemperature/ K/min

-55-50-45-40-35-30-25-20-15-10

-50

30 35 450 5 10 15 20 25 40Time/ min

Argon

0 5 10 15

Temperature/ °C

50

100

150

200

250

300

350

dTemperature/ K/min

-160-140-120-100

-80-60-40-20

0

Time/ min

Helium

However, a lower increase in temperature and maximum speed will be observed

and especially under a sweeping of helium.

This device is composed of a bulky metal cylinder (1) located in the transducer's

base (2) and covered by the radiator (3).

It is mounted at the very beginning of the experiment and used during the whole

experiment.

3

2

1

FIGURE 7: COOLING ACCELERATOR



Under air, nitrogen, argon... the maximum temperature is 500°C.

Under helium the maximum temperature is 300°C and the

maximum speed is 30°C/min.

4.2.3. Cooling with a cryogenic plunging device

4.2.3.1. Device

The device is composed of two inseparable subsets linked by an insulated sleeve.

The cold source itself is a mechanical two-stage cold generator. The fluid is

brought to the exchanger via the insulated sleeve.

The convector is replaced by the exchanger on the furnace.

Cold system stand

FIGURE 8: COLD SYSTEM DEVICE



4.2.3.2. First commissioning

1. The cold system must be on the right side of the DSC 131 to have the cold source naturally positioned and to avoid strength on the transducer. The

system's rear should never be placed against a wall.

The minimum radius of curvature of the sleeve is of 20 cm

2. Installing the base: • Under the base plate, unscrew the last knurled screw on the right side of the instrument.

• Lift the instrument so as to insert the base under the instrument's rear right feet and retighten the knurled screw to fix the base and the body at the same time.

3. Connecting the safety: • Connect the safety cord from the cooling device on the external safety socket (see Figure 9). The ghost connector should be removed.

Sécurité externe

External safety

FIGURE 9: CONNECTION OF THE SAFETY DEVICE

Note When the cold system is not in use, it just remains on its base.

Note Safety can stay constantly connected.

4.2.3.3. Utilization

1. Remove the convector (and cooling accelerator if need be) and replace it by the exchanger. Access to the sample is possible by the top keeping the exchanger

in place.

2. Start the gas circulation.

The sub ambient mode must be used with a dry gas sweeping.



3. Introduce the crucibles and the sample. 4. Determine a temperature close to the ambient (or lower if the user is not interested in a decrease in temperature) using the Direct programming (refer to the Setsoft software booklet).

5. Switch on the switch on the front panel to start the cold system. After a while temperature within the exchanger will start decreasing down to about -90°C.

6. After about 20 minutes the cold system itself will reach its minimum temperature. This temperature is not checked while the scanning temperature

of the DSC 131 is checked by the furnace heating. The instrument is now ready

for use (refer to Chapter 2 - Utilizations and to the Setsoft software booklet).

Minimum and maximum temperatures depend on the sweeping gas

used:

Argon, dry air, nitrogen: -50°C to 400°C

Helium: -80°C to 200°C.

The minimum temperature to be reached directly depends on the

ambient temperature -which will be between 20 and 24°C for the

optimum functioning of cold system.

The sample may be changed while the cold system is still on. However, follow the

instructions below:

1. Determine the furnace temperature at 30°C via the Direct programming window.

2. Increase the gas rate (approximately plus one revolution on the rate adjusting device on the rear panel) to reduce the ambient air inlet when opening the

furnace.

If the gas switching option is available an experiment rate (1.5 l/h) may be

selected on a normally open circuit and a more important rate (about 15 l/h) on the

other circuit.

3. Open the covers and change the sample.

WARNING This must be done rapidly.

4.2.3.4. Stopping the device

1. Stop the cold system using the switch on the front panel. 2. Determine a scanning temperature of 30°C. 3. Remove the cold source after about 20 minutes and place it on its base.

4.2.4. Liquid nitrogen cooling device

The cooling device uses liquid nitrogen to cool down the DSC 131 when used

with temperatures lower than ambient.

A container of liquid nitrogen is placed where the convector is located. This

container is of about 1.5 liters.



WARNING The use of subambient mode requires the cooling fan to be switched off.

When the container is installed fill it up with liquid nitrogen.

The level of liquid nitrogen must always be high enough in order to avoid an

uncontrolled increase in temperature.

Fan

Liquidnitrogencontainer

FIGURE 10: COOLING DEVICE

Liquid nitrogen can burn your skin severely. Therefore, wearing

gloves and glasses is recommended when the container is refilled.

Note In order to avoid an uncontrolled cooling process, the DSC 131 must be on

regulation at 20°C for instance, before being filled with liquid nitrogen.

WARNING Circulation of inert gas (helium) is necessary for the instrument to work properly at very low temperature. Argon and nitrogen should be avoided at

very low temperature as these two gases partly liquefy.

5. Commissioning of the calorimetric transducer

5.1. Presentation

The furnace-transducer set is hermetically closed either by the convector (1) or by

the container of liquid nitrogen. Tightness is ensured by an o-ring (2).

When the convector or the container is removed, a protecting shutter closes the

hole and only the part of the transducer to be used is displayed.



The transducer is made of:

• a machined metallic plate (8) providing for two housings for the measure and reference crucibles. A thermocouple is welded under each housing to perform

the differential measurement.

• a temperature measurement thermocouple in the middle of the plate. • a four-wire shaft receiving the various connecting wires.

The transducer is placed in a silver block (3), centering is ensured by three

adjustable screws (4) supported by the shaft.

A heating element (5) surrounds the block and provides for heating. The

regulation thermocouple (6) provides for temperature control and measurement.

A stopper (7) closes the upper part of the chamber.

The gas is introduced into the lower part of the analysis chamber via a stainless

steel tube (10).

A hole (9) in the cover (7) lets the gas out of the analysis chamber.

1

8

5

9

7

34

2

Gas inlet Gas outlet

6

10

FIGURE 11: DSC131 SECTION

5.2. Commissioning

• Switch on the supply rack on the rear panel to use the transducer and the instrument. A green light appears on the front panel.

• Switch on the computer and the printer (see corresponding manual). • Start with Collection on the Setsoft. On the Display menu, choose Direct

programming. In this window, furnace and sample’s temperatures are shown



as well as the Heatflow signal. We can fix a regulation temperature, start the

ventilator and commute a sweeping gas (option).

• To accede to experiment chambers: • remove the convector (1) • close the protecting shutter • remove the stopper (7) using laboratory pliers introduced in the two recessed holes

• the "measure" crucible is at the front of the instrument while the "reference" crucible is at the rear.

The DSC 131 can start carrying out experiments. Refer to the Utilization and Setsoft booklets.

6. Technical characteristics

6.1. DSC 131

• Single-phase electric network 230 V + - 10 % 50/60 HZ

• Total power consumed 320 VA

• Safety equipment Programmable safety temperature

through a software

Thermoswitch of safety on the

transducer

• Gas inlet pressure 3 bar maximum

• Working ambient temperature From 5°C to 40°C

• Relative humidity Maxi. 80% at ambient

temperatures up to 31°C,

decreasing to 50% at 40°C.

• Dimension W x H x D

DSC

DSC + cryogenic device

DSC + Liquid nitrogen tank

420 x 350 x 530

435 x 350 x 530

420 x 780 x 530

• Weight DSC 23 kgs

• Working temperature’s range From –150°C up to 700°C. Those

values will be entered in relation

to the options, crucibles or

sweeping gas used.

Consequently, it is imperative to

refer to the instructions leaflet.



• Programming speed From 0.001 to 50°C/minute.

Those values will be entered in

relation to the options or

sweeping gas used. Refer to the

instructions leaflet.

• Sample’s maximum volume

Aluminum crucible : 30 µl

Aluminum crucible : 100 µl

HP crucible: 30 µl

• Liquid nitrogen tank’s filling volume 2 liters

6.2. Cryogenic device

• Electric network’s power supply 220 V / 50Hz

• Total power consumed 1 KVA

• Safety equipment Thermoswitch

• Working ambient temperature 22°C (optimum)

• Working relative humidity 50 % (optimum)

• Dimension ( W x H x D ) 250 x 480 x 510

• Weigh 32 kgs

• Range of working temperature From -70°C up to 400°C. Those

values will be variable in relation

to the sweeping gas used. Refer

to the booklet.

6.3. Materials in contact with the gas

Tubing Polyurethane

Connector Brass

Analysis chamber Stainless steel, silver, Dural

Sensor Chromel, Constantan, alumina

Crucible Aluminum, incoloy

6.4. Conforming to standards

Emission standard: EN 61326-1 (July 1997) and

EN 61326/A1 (October 1998)



Immunity standard: EN 61326-1 (July 1997) and

EN 61326/A1 (October. 1998)

European basic standard: EN 55022 Class B (December 1994)

Harmonized standard: EN 61010-1 (August1993) and EN 61010-1/A2

(November 1995)



Appendix Table of the Polyurethane chemical compatibility

Substance Family Compatibility

Acetone Ketones Not recommended

Acetonitrile Nitriles Weak

Aluminum Salts Aluminum Compounds Good

Barium Salts Barium Compounds Good

Benzyl Alcohol Hydroxyl Compounds Weak

Boric Acid Inorganic Acids Good

Butanol Hydroxyl Compounds Good

Calcium Chlorite Calcium Compounds Good

Carbon Disulfide Sulfur Compounds Weak

Cupric Chloride Copper Compounds Good

Cyclohexanone Ketones Not recommended

Dichloromethane Halogen Compounds Not recommended

Diethylamine Aliphatic Amines Weak

Diethylformamide Aliphatic Amines Not recommended

Ethyl Acetate Carboxylic Esters Weak

Formaldehyde Aliphatic Aldehydes Good

Gasoline Aromatic Hydrocarbons Good

Glycol Ether Ethers Good

Hexane Aliphatic Hydrocarbons Good

Hydrochloric Acid

(37%) Inorganic Acids Not recommended

Hydrogen Peroxide

(30%) Peroxides Weak

Hydroflouric Acid (48%) Inorganic Acids Not recommended

Jet Fuel (JP-5) Aliphatic Hydrocarbons Good

Kerosene Hydrocarbons Good

Methanol Aliphatic Hydroxylic

Compounds Good

Methyl Ethyl Ketone Aliphatic Ketones Not recommended

Mineral Oil Aliphatic and Alicyclic

Hydrocarbons Good

Naphtha Hydrocarbons Good

Nitrobenzene Nitro Compounds Not recommended

Phenol Aromatic Hydroxylic

Compounds Not recommended

Propylene Glycol Hydroxylic Compounds Good

Sodium Hydroxyde

(50%) Inorganic Bases Good

Sulfuric Acid (98%) Inorganic Acids Not recommended

Sulfuric Acid (50%) Inorganic Acids Not recommended

Tetrachloroethylene Halogen Compounds (Vinyl Good



Halides)

Tetrahydrofuran Alicyclic Ethers Not recommended

Toluene Aromatic Hydrocarbons Weak

1,1,1-Trichloroethane Aliphatic Halogen Compounds Weak

Trichloroethylene Halogen Compounds (Vinyl

Halides) Weak

Triethylamine Aliphatic Amines Good

Turpentine Hydrocarbons Good

Water Misc. Good

Those indications are provided as information and are not

necessarily reliable for all the conditions for use.

We are not responsible in any way for this table as safety or

guarantee terms towards our instrument.

DSC 131 - Commissioning/Utilisations

Utilizations 20 G/DSC131-1A – 07/07/06

CHAPTER 2 - UTILIZATIONS 1. Selecting the crucible

The crucible selected for the sample analysis very often determines the quality of

the analysis. This is a vital choice that depends on the sample to be analyzed and

the application to be carried out.

Three types of crucibles are available with the DSC 131:

• low-volume aluminum crucible (30 mm3) • medium-volume aluminum crucible (100 mm3) • high-pressure crucible (30 mm3)

The crucible depends on the sample to be analyzed. As a general rule:

• Use a low-volume aluminum crucible to analyze a small mass of solid sample so as to have a shorter response time from the DSC transducer.

• Use a medium volume aluminum crucible to analyze a larger mass of solid sample and liquids at a medium temperature.

• Use a HP crucible to analyze samples with high vapor pressure and liquids.

Choosing the crucible’s volume depends on the mass of sample to be analyzed. As

a general rule, analyze a small mass of sample (about 10 mg) so as to minimize

the effects of a thermal gradient within the product.

However, if a low thermal effect is to be measured, use the largest mass of sample

available.

The various recommendations given above cannot cover all the

instrument’s applications.

Before analyzing a new product you have to get information

about the risks of corrosion for the crucible during the heating or

one of the possible transformations (fusion, decomposition...).

This is a vital choice as it determines the outcome of the

experiment. Making the wrong choice can lead to damaging the

crucible, and thereby damaging the DSC transducer.

Follow the instructions in force to eliminate the samples which

could be dangerous towards the environment.



1.1. Low-volume aluminum crucible

WARNING Can be used only up to 550°C

1.1.1. Description

The low-volume aluminum crucible is not fluid-tight and is made of (Figure 12):

• a 0.2 mm-thick stamped aluminum tray with a flat bottom. • a 0.12 mm-thick stamped aluminum cover to be fitted into the tray.

FIGURE 12: LOW VOLUME ALUMINIUM CRUCIBLE

1.1.2. Crimping

Use a crimping tool composed of a matrix (1) and a punch (2) to close the

crucible (see Figure 13).

FIGURE 13: CRIMPING TOOLS

In practice, once the weight of the sample plus the crucible is known:

1. Place the crucible in the matrix opening. 2. Place the cover on the crucible and slightly introduce it. 3. Fit the punch on the matrix. 4. Place the whole set on a flat surface and 5. Press with your hand to drive the punch in the matrix down to the stop.



6. Remove the crucible.

WARNING The DSC 131 will give the correct measure only if the bottom of the crucible is perfectly flat so as to provide a good thermal contact with the detector.

Check that the bottom of the crucible is flat after the crimping operation. Change

the crucible if the surface of the bottom is uneven.

1.1.3. Utilization

The low-volume aluminum crucible is recommended for the DSC 131 because the

bottom of the crucible is thin and therefore its low thermal mass ensures a short

response time of the DSC.

This crucible is to be used with small weights of samples (a few mg).

The samples can be:

1. solid such as mineral, organic and metallic samples, as well as powders, films, grains,....

WARNING Be very careful before starting the analysis:

Make sure that the sample will not corrode the aluminum crucible during heating

at high temperature or after the transformation (fusion for a metal or a mineral

sample for instance).

As the crucible is not fluid-tight, make sure that the sample will not overflow, and

thereby lead to damaging the transducer. If you are not sure about an experiment,

heat the crucible in a small furnace before performing the experiment.

2. liquids at low temperature

As the crucible is not fluid-tight, do not use the low-volume

crucible above 50°C when testing liquids because of evaporation.

Indeed, the thermal effect corresponding to evaporation may hide

the effect to be measured.

Make sure that the crucible is not completely filled in order to

prevent the overflowing during the crimping process.

Do not analyze corrosive liquids in this type of crucible.

As for applications, the low-volume aluminum crucible is perfectly adapted to

following measure:

• state transformation (fusion, crystallization) • phase transitions, polymorphism



• glass transition • cross-linkage • dehydration • oxidation (when a coverless crucible is used)

The low-volume aluminum crucible cannot be re-used after the

analysis.

1.2. Medium-volume aluminum crucible

WARNING Can be used only up to 550°C

1.2.1. Description

The medium-volume aluminum crucible is composed of (Figure 14):

• a 0.3 mm-thick and 5.5 mm-high pressed aluminum tray with a flat bottom • an aluminum cover (3 different types are available):

♦ hard aluminum cover (S60/12727) ♦ standard cover (2) ♦ cover with a hole (3)

2 3

FIGURE 14: MEDIUM VOLUME ALUMINUM CRUCIBLE WITH COVER

1.2.2. Crimping

In case of high vapor-exhibiting reactions, excess pressure may

be produced in the crucible depending on the type of crimping.

The use of a pierced cover is highly recommended so as to avoid

excess pressure and prevent the crucible from exploding.



Metal crucibles are closed using an appropriate crimping tool (Figure 3).

After weighing the sample in the crucible, proceed as follows:

The template (A) receives the crucible to be crimped and holds it in position

during crimping.

FIGURE 3 : CRUCIBLE CRIMPING TOOL

The punch (B) crimps the lid onto the crucible. After the crimping operation,

make sure that crimping is correct. Check in particular that the lid is not askew.

WARNING The templates act as gauges for checking the diameter of the crucibles, or more generally of any experimental element or fitting introduced into the

calorimeter. No element or fitting must be introduced into the calorimeter if it

cannot pass through the template.

WARNING Check that the bottom of the crucible is not uneven after the crimping, as for the low-volume crucible (refer to Warning in paragraph Low-volume aluminum crucible).

A compact sample in the crucible may be more adapted to some applications or

samples to be analyzed as a better thermal contact is ensured and vapor pressure is

maintained above the sample (e.g. dehydration of gypsum and plaster).

The crucible with a standard cover or a cover with a hole is to be

used for investigations on solids and powders. For liquids, use a

HP crucible.

A

B



Check that the product to be analyzed does not corrode

aluminum.

The crucible cannot be re-used.

Use the HP crucible for investigations under high internal

pressure.

If the sample is a liquid do not entirely fill the crucible so as to

have enough expansion volume for the liquid.

Check the crucible tightness: test the sample before using the

DSC (in a small furnace for instance).

Check that the liquids analyzed do not corrode aluminum.

The crucible cannot be re-used.

1.2.3. Utilization

The aluminum medium volume crucible is used when a quite large mass of

sample is to be analyzed. As the thermal mass is higher the response time from the

DSC 131 is longer when this type of crucible is used.

The standard cover is mostly used when solids, powders, films... are investigated.

The pierced cover is used when products are undergoing dehydration.

The pierced cover is also used when interaction between a reactive gas and the

sample is investigated (e.g. oxidation). For this type of application the sample can

be placed in a coverless crucible.

See the limits in the previous paragraph.



1.3. High Pressure crucible 500 bars 600°C S60/581 86

In many applications, the sample must be placed into a fluid-tight crucible to keep

the vapor inside during the heating, as the thermal effect (vaporization) would

hide the chosen thermal effect (decomposition, polymerization...). The HP

crucible is perfect for this type of application.

1.3.1. Description

In many applications, the sample needs to be isolated in a fluid-tight crucible to

prevent any vapor release during heating, as the thermal effect (vaporization)

would mask the thermal effect under study (decomposition, polymerization, etc.).

In such cases it is possible to use crucibles with non-controlled pressure that meet

the European standard for pressurized containers (CE97/23). They can work at up

to 500 bars and 600°C and feature a safety device that allows excess pressure to

be released.

WARNING The gilded Cell S60/58159 can be used only up to 400°C

Their use implies that sometimes the internal pressures in the crucible are very

high and often poorly known. Before using these crucibles, a number of

recommendations must be applied.

WARNING A poorly controlled phenomenon can result in serious damage that is

not covered by the manufacturer's warranty (comply with the crucible utilization

limits).

WARNING Never undertake an experiment that could produce high pressures

without studying it beforehand by heating one or more crucibles loaded with

samples in the same way in an adjacent furnace, but at a rate and at a temperature

slightly higher than those planned.

WARNING Pay attention to the very rapid rise in the saturation pressure as a

function of the temperature. Leave sufficient volume for the liquids to expand.



FIGURE 4: FLUID-TIGHT NON-CONTROLLED PRESSURE CRUCIBLES . (THE HEIGHT SHOWN ON THE DRAWING IS THE SENSYS CELL ONES)

The crucible has a machined body and a tapered cap that screws into the body.

1.3.2. Crimping

The crucible is closed by fitting its screw-in cap and tightening it to the necessary

and sufficient torque. The cap 1-Figure 5 has a top section that enables it to be

screwed into the body of the crucible 2-Figure 5 and which breaks when the

correct tightening torque is applied. This guarantees resistance to a pressure of

500 bar. A 6-mm open-end wrench is used to tighten the cap.

FIGURE 5 FLUID-TIGHT NON-CONTROLLED PRESSURE CRUCIBLE . (THE HEIGHT SHOWN ON THE DRAWING IS THE SENSYS CELL ONES)

Tool S60/58163 is used to hold the crucible in position. When the crucible is held

with the tool, tighten the tool with the screw until the crucible is not rotating.

Tighten the cap with the open-end wrench Figure 7. Tighten until the top section

of the cap breaks off Figure 8, indicating that the right tightening torque has been

applied.

2-crucible body

1-cap

1-cap with break-

off top section

2-crucible body

Positioning of the

tight crucible

SENSYS: S60/58158

or

DSC131: S60/58186

Screw



FIGURE 6 TOOL FOR HOLDING THE FLUID -TIGHT CRUCIBLE .

Remarque These crucibles are in accordance with the European standard for containers under pressure (CE97/23) and they can be used with non-dangerous and

dangerous gases of class 2 and class 1. Be careful gas panel furnished by

SETARAM are only working with non-dangerous gases of class 2

WARNING The maximum use temperature is of 600°C. The pressure must not exceed 500

bars.

A 6-mm open-end wrench is used to tighten the cap as shown on Figure 7. The

wrench is provided with the tool: S60/58305

FIGURE 7 CLOSING OF THE CRUCIBLE

Positioning of the

tight crucible

SENSYS: S60/58232 Tool S60/58163



Figure 8 After breaking

If the sample is a liquid, do not fill the crucible too much. The

level of the liquid must be below the shoulder on which the

stopper lays.

Make sure that the groove is not humid and dry it if necessary.

Humidity can lead to a thermal effect related to water

evaporation.

1.3.3. Utilization

1.3.3.1. Instructions for use

The HP crucible is particularly well adapted to investigate decomposition of

organic products, polymerizations, reactions with a high internal pressure.

The crucible provides for tightness up to very high internal pressures.

However, internal pressure is often not well known and some recommendations

are necessary before starting this type of experiment:

If a crucible explodes in the calorimeter (the stopper is expelled

when pressure is too high), it may cause damages which are not

guaranteed by the manufacturer. It is vital to respect the limits for

the metal seal used.



Before carrying out an experiment that might lead to high

pressure, heat in a furnace one or several crucibles similarly filled

at a scanning rate and temperature slightly higher than necessary

for the investigation.

As a general rule, a preliminary experiment with a small mass of

sample is recommended especially when decomposition is

investigated (1 to 2 milligrams). Decomposition phenomena are

generally highly exothermic. If the thermal phenomenon is low,

amplify the scanning rate instead of increasing the sample mass.

Enough expansion volume above the sample is necessary, in

order to analyze liquids.

Should the first experiment be dangerous, stay near the

instrument in order to stop the experiment if need be.

When higher than 300°C the crucible needs to be atmospheric

corrosion-tight. The transducer must be swept by an inert gas.

The cell can be used only once.

2. Preparing the experiment

Once the crucible is selected (see section Selecting the crucible) and the necessary

precautions are taken, the experiment requires various operations:

1. Weighing a sample 2. Arranging crucibles in the DSC 3. Selecting the sweeping gas 4. Entering the experiment conditions 5. Recording signals 6. Processing data

2.1. Weighing a sample

The sample can be a liquid or a solid (powder, granule, film ...). In both cases, the

sample represents the product to be analyzed and must be carefully used.

Weigh the sample in the crucible, using a balance providing a measurement

accuracy of 0.01 mg.

Note Use the highest mass of sample is the chosen thermal effect is low.



Note If close thermal effects are to be separated, use a small mass of sample so

as to decrease the thermal gradient effect in the sample and to improve the peaks

separation.

If the sample is explosive, weigh only a few milligrams of

sample.

Make sure that the crucibles are not filled up above the space

necessary to the crimping process.

Before closing the crucible, check that the groove is clean.

After the crimping, check that the bottom of the crucible is still

flat and even.

2.2. Placing crucibles in the DSC

1. Remove the convector and close the protecting shutter. 2. Remove the metal stopper protecting the experimental chamber to reach the actual transducer.

3. Place the crucible with the sample in the right chamber or the sample chamber of the transducer. Check that the crucible is properly centered and

arranged in the chamber.

4. In the left chamber, place a crucible that is similar to the one in the right chamber and of the same type.

The crucible could be:

• empty, in case of a low mass sample or a high thermal effect measurement.

• filled with an equal mass of alumina (previously calcinated) if the sample mass is important or the thermal effect to measure is low.

The reference crucible mainly compensates the thermal effect due to the specific heat of the sample.

In practice, the reference crucible remains empty when the low volume aluminum crucible is used. When the medium volume crucible is used, it may be

useful to fill it with alumina.

If a liquid is analyzed in a tight crucible it is recommended to use distilled water

as a reference but the instructions for use given in the chapters referring to

crucibles must be taken into account.



5. Set the metal stopper. 6. Close the instrument with the convector.

2.3. Selecting the sweeping gas

(Connections of the sweeping gas circuit are described in paragraph 4.1. in the

Commissioning chapter).

The DSC 131 offers various possibilities:

• Do not use sweeping gas: generally with aluminum crucibles when temperature is above 0°C.

• Use an inert sweeping gas (argon, nitrogen, helium): the sweeping gas is used to prevent the sample from oxidizing (with opened crucible).

WARNING The calibration of the DSC transducer varies with the type of gas used. See Energy calibration in the present chapter.

• Use an active sweeping gas (oxygen, hydrogen): the sweeping gas is used to investigate the sample/sweeping gas reaction with an opened crucible.

Before investigating a reaction between a sample and a reactive

gas, make sure that the transducer is not likely to corrode or be

damaged due to a violent reaction.

• Use an inert gas and then a reactive gas: in some investigations (determination of induction time for oil for instance), first, the sample must be protected under

inert gas, and then the inert gas is replaced by an oxidizing gas (air, oxygen) in

order to oxidize the sample.

WARNING Use gases having a close density (argon and oxygen for instance). Indeed, the flow of both gases must be adjusted so as when changing the gas, the

DSC signal is not disturbed. Use the device for automatic commutation of gases

(option) as this operation is performed via the computer.

WARNING It is forbidden to use corrosive and/or reducing gases.

In any case, if the temperature exceeds 500°C in isothermal mode

or 60°C in programming at speed at a least equal at 5°C/min, the

transducer must be protected by a neutral gas.

2.4. Entering experimental conditions

This part of the experiment is also detailed in the software booklet which provides

information related to the test to be carried out from the computer.

In this paragraph, additional instructions on the experiment itself are given:



• Scanning and sequencing • PID actions • Safety temperature • Control of the electrovalve and cooling fan

2.4.1. PID actions

The regulation of the DSC 131’s furnace is done via a K thermocouple. PID

coefficients for regulation must be entered in the computer so as to regulate the

furnace.

PID values are expressed in:

• °C for P (Proportional) • Seconds for I (Integral) • Seconds for D (Derivative).

The values to be used in the software are as follows:

P 50

I 50

D 5

These values apply to the whole temperature range of the DSC 131.

2.4.2. Safety temperature

Entering a safety temperature is vital for protecting the DSC transducer, the

sample and the crucible, depending on the experiments to be carried out.

In general, the following values are to be recommended:

• If the work is performed over the whole temperature range set the value for the safety temperature at the maximum operating temperature plus 20°C.

• If protection is required for the sample under analysis so as to prevent decomposition, oxidation, etc or for a crucible as a function of its temperature

capacity, set the value for the safety temperature at the protection temperature

chosen.

Temperature scanning automatically stops at the selected temperature should there

be a problem or previous errors.

2.4.3. Control valve and fan

The valves window is used to control both the fan and the gas automatic commutation device (option).



• The fan is switched on by activating the second box of the valves window.

In the list of sequences, the Valves column must be following (0100 0000)

• Gas 1 is normally on when no specific command is requested. By activating the first box of the valves window, gas 1 is replaced by gas 2.

In the list of sequences, the Valves column must be following (1000 0000)

FIGURE 24: CONTROL ELECTROVALVE AND FAN

2.4.4. Scanning and sequencing

Before starting the experiment, a sample scanning cycle needs to be prepared. To

do this, the software offers a sequence-gathering table which carries out heating

and cooling operations, as well as periods of constant temperature.

In practice, two types of sequence are available: scanning and isothermal

sequences.

1. For a scanning sequence, supply the initial and final temperatures, as well as the scanning rate during this sequence. The table shows the duration of the

scanning sequence (See figures 25 and 26).

2. For an isothermal sequence, supply the level temperature (°C) and the length of the level (sec.).

An experiment is defined as a collection of scanning and isothermal sequences.

Here are a few examples to understand the functioning:

Fan

Electrovalve



2.4.4.1. Simple cycle

The simplest, and often the most common cycle, involves heating a sample

continuously and cooling it.

In that case it is necessary to set:

1. An isothermal level at the start temperature (generally, a few degrees below ambient temperature) so as to produce stability in the DSC signal before the

start of the heating for 300 seconds.

2. A scanning sequence with the initial and the final temperature in the test, as well as the selected scanning rate.

3. An isothermal level at the final temperature, to have a stable DSC signals for 300 seconds.

4. A scanning sequence with its initial temperature as the one reached, and the final temperature as the initial one.

The graph (Figure25) is a means of checking that parameters entered in the

computer are correct.



FIGURE 25: SIMPLE CYCLE

Refer to the software booklet Setsoft for the cycling operations in such an experiment. This operation is interesting to plot a base line for a given sample that

does not transform during the second heating.

2.4.4.2. Staged cycle

The staged cycle provides for carrying out heating or cooling in various stages.

For example:

1. An isothermal level at the start temperature for 300 seconds. 2. A scanning sequence with the initial temperature and the intermediate temperature at an initial scanning rate.



3. An isothermal level at the intermediate temperature. 4. A scanning sequence from the intermediate temperature to the final temperature at a second scanning rate.

5. A scanning sequence from the final temperature to the start temperature at a cooling rate.

FIGURE 26: STAGED CYCLE

Working from these two examples, more complex cycles can be produced

depending on the experiment’s requirements. 250 sequences are available to

carry out this work.



The valves window is used if the gas automatic commutation device is used. Gas 1 is normally on when no specific command (0000 0000) is requested. By

activating the electrovalve (1000 0000), gas 1 is replaced by gas 2.

When using the cooling accelerator the maximum temperature is

500°C under air, nitrogen, argon ...and 300°C at 30°C/min under

helium.

WARNING The value for the cooling rate must be provided as positive.

2.5. Making use of the test

After entering the experimental conditions, start scanning the temperature cycle

and record the thermogramme.

2.5.1. Thermogramme

Working from the first recorded thermogramme, replot it as a function of either

time or temperature by optimizing the axes via the Zoom functions.

As a general rule, preference is given to representing as a function of the more

expressive temperature so as to situate the products transformation temperatures.

However, if the cycle contains a succession of scanning sequences and isothermal

levels representing as a function of time provides for an overall display of the

phenomena.

Two types of phenomena are shown on a thermogramme:

1. Endothermic phenomena such as fusion, phase transition, glass transition, evaporation, etc.

2. Exothermic phenomena such as crystallization, decomposition, oxidation, polymerization, etc.

Endothermic peaks are commonly directed toward the bottom of the

thermogramme and the exothermic peaks toward the top (see figure hereafter).



Heat flow

EXO

temperature in °C

50 100 150 200 250 300 350

-35

-30

-25

-20

-15

-10

0

10

15

5

FIGURE 27: ENDOTHERMIC AND EXOTHERMIC PEAKS

When making use of the thermogramme, the first operation involves identifying

the various transformations and specifying them as endothermic or exothermic

effects.

2.5.2. Determining transformation temperatures (or times)

In this section, three types of transformation are available:

1. Endothermic transformation such as fusion or phase transition 2. Exothermic transformation such as crystallization or reaction 3. Glass transition The methods used for determining the transformation temperatures (or times)

comply with the international ISO standards in force or in draft.

2.5.2.1. Endothermic transformation

The endothermic transformation thermogramme is shown below:

heat flowT Tim eim Tfm

temperature

Tefm

Tpm

FIGURE 28: ENDOTHERMIC TRANSFORMATION THERMOGRAMME



The following temperatures (or times) are determined:

• Temperature Tim (or time tim) at the peak start corresponding with the peak’s take-off in relation to the base line plotted between the start and the end of the

peak.

• Temperature Teim (or time teim) corresponding to the onset temperature, i.e. the intersection between the base line and the tangent at the peak inflexion

point in the increasing phase.

• Temperature Tpm (or time tpm) corresponding to the top of the peak.

• Temperature Tefm (or time tefm) corresponding to the endset temperature, i.e. the intersection between the base line and the tangent at the peak inflexion

point in the decreasing phase.

• Temperature Tfm (or time tfm) at the peak end corresponding with the peak returning to the base line.

heat flow

time (s)

EXO

2,5

0,0

-2,5

-5

-7,5

-10

1560 1620 1680 1740 1800

temperature

Teim

FIGURE 29: THERMOGRAMME OF THE FUSION OF A PURE SUBSTANCE

In the particular case of a pure crystalline substance, the fusion temperature is

measured at the onset Teim (Figure 29).

Refer to the Practical Works chapter for additional explanations.

For semi-crystalline substances, like numerous polymers, the fusion (or softening)

temperature is measured at the Tpm temperature on the top of the peak.

2.5.2.2. Exothermic transformation

The exothermic transformation thermogramme is shown hereafter:



heat flow

temperature

exo

TicTeic Tefc Tfc

Tpc

FIGURE 30: THERMOGRAMME OF AN EXOTHERMIC TRANSFORMATION

The following temperatures (or times) are determined:

• Temperature Tic (or time tic) at peak start corresponding with the peak’s take-off in relation to the base line plotted between the start and the end of the peak.

• Temperature Teic (or time teic), corresponding with the onset temperature, i.e. the intersection between the base line and the tangent at the peak’s

inflexion point in the increasing phase.

• Temperature Tpc (or time tpc) corresponding with the top of the peak.

• Temperature Tefc (or time tefc) corresponding with the endset temperature, i.e. the intersection between the base line and the tangent at the peak’s

inflexion point in the decreasing phase.

• Temperature Tfc (or time tfc) at the peak end corresponding with the peak returning to the base line.

In the same way as for fusion the crystallization temperature in a pure, crystalline

substance is measured at the onset temperature Teic.

For a semi crystalline substance, crystallization is measured at the temperature

Tpc on the top of the peak.

2.5.2.3. Glass transition

Given what we know at the moment, glass transition corresponds with the

progressive change in the properties of a solid to those of a viscoelastic liquid.

As glass transition is a progressive process it is distinguished by three distinct

temperatures (Figure 31):



T

T

T

ig

g

eg

FIGURE 31: GLASS TRANSITION WITHOUT RELAXATION TIME

• The temperature at the start of transition Tig given by the intersection between the base line (before the transition) and the tangent at the inflexion point (line

of the largest slope).

• The temperature at the end of transition Teg given by the intersection between the base line (after the transition) and the tangent at the inflexion point.

• The conventional temperature for glass transition Tg produced by the intersection of the curve and the half-way line between the two base lines.

If the sample shows any aspect of relaxation before or after the glass transition,

proceed as described in Figure32:

T

T

T

ig

g

eg

FIGURE 32: GLASS TRANSITION WITH RELAXATION TIME

2.5.3. Temperature correction

Measuring the sample’s temperature is performed through a platinum probe in the

calorimetric unit.

Although this measurement is done near the sample, a small difference may be

noted with the sample’s real temperature due to the thermal gradient and the time

for the heat to cross the crucible wall and detector.

Temperature correction will vary according to:

• The scanning rate used • The type of crucible involved • The type and rate of sweeping gas

Standard materials with known fusion or transformation points are required to

carry out this temperature correction.



2.5.3.1. Standard materials

Metals are preferable for determining temperature calibration of the DSC 131 as

shown in the table below:

Substance Melting point (°C)

Mercury -38.86

Indium 156.598

Tin 231.94

Lead 327.47

Reference : ENR7-6ET01 (Annex A)

For these metals, choose a purity of 4N (99,99 %) or even better 5N (99,999%).

However, depending on the range of temperature planned for analysis, inorganic

and organic substances may be used for fusion and transition:

Substance Temperature (°C)

Cyclohexane -86.91

Potassium Nitrate 128

Silver sulfate 424

Quartz 571

Reference : ENR7-6ET01 (Annex A)

When using these substances special attention must be paid to

substances exhibiting high vapor pressures.

In addition, certain substances can break down if heated beyond

their transition or fusion temperature. It is thus VITAL to remain

within the temperature measurement corresponding with the

transformation given in the table.

Some substances can react to the crucible material. A table of

compatibility between substances and crucible materials is

available in Annex C.

2.5.3.2. Experimenting

Choose at least three standard materials comprising the temperature zone to be

used for analyzing the samples.

Set the experimental conditions to be used for analyzing the sample, especially:

• Type of crucible • Type and flow rate of the sweeping gas • Temperature scanning rate



For each standard material:

• Weigh about 50 mg of substance in the crucible. • Arrange the crucible on the sample side of the DSC transducer. Arrange an identical, empty crucible on the reference side.

• Close the furnace and switch on the sweeping gas. • Prepare the scanning cycle so as to get the substance molten.

In practice, scan the furnace temperature rapidly (30°C/mn) up to around 30°C

before fusion. After an isothermal stabilization level record the fusion at the

chosen rate.

• Finally, scan the furnace’s cooling.

FIGURE 33: EXAMPLE OF THE CYCLE SCANNING



• Record the corresponding thermogramme and replot the part corresponding to the standard’s fusion as a function of temperature.

• Repeat the operation for each material, adjusting each time the temperature range for measuring the fusion or transition.

Note Expand the temperature range for analyzing fusion when the scanning rate

increases.

Note A second fusion of the sample is recommended after cooling and the

second thermogramme provides useful information. The first fusion does provide

a compact shape to the sample, which is more helpful for the heat exchange with

the transducer.

2.5.3.3. Temperature correction for a fixed scanning rate

For each fusion peak determine the onset temperature Teim as defined in paragraph 2.5.2.1.

If:

• Teim, the onset temperature measured • Tfi the real fusion temperature for sample i

• dTi = Teim - Tfi the temperature correction

Draw up a table (Teim, Tfi, dTi) and plot the variation dTi = f (Teim) (see Figure

below).

∆∆∆∆ T i

V = 5°C mn -1

10

8

6

4

2

162,8 239,5 336,9 430,5

Tei

pente = a

∆ T = ∆∆∆∆i iT + a Ti

FIGURE 34: TEMPERATURE CORRECTION FOR A FIXED SCANNING RATE

Express this variation in the form of a straight line:

dTi = B0 + B1. Teim



Determine B0 and B1 using a regression program.

Enter the values of B0 and B1 on to the software’s Parameter window for temperature correction.

Reset the values B2 and B3.

Note This relationship provides for correcting any temperature for the analysis

interval considered and by always using the same scanning rate.

2.5.3.4. Temperature correction for various scanning rates

If analyzing the sample has to be done at various temperature-scanning rates the

fusion of the standard materials needs to be studied at various scanning rates Vi.

In practice, carry out experiments for each standard using at least three different

rates, the values of which encompass the values of the rates to be used for the

sample.

Draw up a table (Teim, Tfi, Vi, dTi).

Determine the coefficients Bo, B1 and B2 for the correction relationship using the

least squares method or a regression program: dTi = B0 + B1. Teim + B2. Vi

In practice, if N is the number of tests carried out, calculate the following sums∑:

A ∑Teim

B ∑Vi

C ∑dTi

D ∑Teim2

E ∑Teim. Vi

F ∑Teim. dTi

G ∑Vi2

H ∑Vi. dTi

Here the coefficients are produced by the relationships:

B0 =

J

W B

1 =

K

W B

2 =L

W

where:

W = N (DG - E2) - A2G + 2ABE - DB2



J = C (DG - E2) - F (AG- EB) + H (AE - DB)

K = N (FG - HE) - A (CG - BH) + B (CE - FB)

L = N (DH - EF) - A (AH - EC) + B (AH - DC)

The temperature correction thus determined applies for any scanning temperature

and rate for the range investigated.

Enter the values B0, B1 and B2 in the software’s Parameter window for

temperature correction.

The coefficient B3 is reset for the instrument used.

WARNING During experiments for determining temperature correction, check that the values B

0, B1, B2 and B3 are reset in the software.

2.6. Energy calibration

It is necessary to carry out an energy calibration of the DSC 131.

The DSC transducer can be calibrated by using standards so as to transform the

electrical signal S (in microvolt) into thermal power P (in milliwatt). Then, a

calibration coefficient K is determined:

S = K. P

The calibration coefficient K varies with various parameters:

• The temperature of the experiment • The type of crucible • The type and flow of sweeping gas

Paragraph 2.6.1 (hereafter) shows the means of calculating the calibration

coefficient K.

2.6.1. Measuring the fusion heat of a pure substance

The thermogramme representing the fusion of a pure substance is shown in Figure

below (refer also to the Practical Work chapter):



temperature °C

EXO

heat flow (mW)

-10

-7,5

-5,0

-2,5

0,0

2,5

157 158 159 160 161

TPR

FIGURE 35: FUSION OF A PURE SUBSTANCE

The heat of fusion for the sample analyzed is produced by integrating the area

under the peak between the peak’s start Tim and end Tfm temperatures.

Without initial calibration the ordinate is expressed in µV and the abscissa in seconds, the peak area is expressed in µV. s.

Integrating the peak is done via the Integration function on the base software once the type of base line is selected. For a fusion peak, use a straight base line

between the temperatures Tim et Tfm.

2.6.2. Standard materials

Paragraph 2.5.3.1. provides a table of standard metals for determining the

temperature correction.

For energy calibration the same standards may be used as they are thermally

stable and offer the facility of being used for numerous and successive tests

without modifying their specifications.

Their fusion heat contents are used for energy calibration.

Substance Fusion heat content

(J / g)

Fusion heat content

(°C)

Mercury 11,469 -38.86

Indium 28,51 156.598

Tin 60,21 231.94

Lead 23,00 327.47

ENR7-6ET03 (Annex B)



Based on the sample transformation temperature the standard chosen for energy

calibration will be the one with a melting point closest to the transformation

temperature of the sample.

As for determining temperature correction, an inorganic substance may be used

for energy calibration.

Substance Fusion heat content (J / g) Melting point (°C)

KNO3 53,2 128

ENR7-6ET03 (Annex B)

Note Certified Reference Materials (CRM)

Note For measurements requiring a higher accuracy, some Certified Reference

Materials for temperature calibration (or temperature and fusion heat calibration)

are available in national laboratories such as the National Institute of Standards

and Technology (NIST-USA) and the Laboratory of the Government Chemist

(LGC-GB). These Certified Reference Materials enable the traceability of the

measurements (Cf. Annex A and B)

2.6.3. Experimenting

Choose one or several standards based on the transformation temperature range

investigated.

The experimenting conditions are similar to those described in paragraph 2.5.3.2.

Plot the fusion curve as a function of time or temperature.

Note In practice temperature and energy calibrations are carried out with the

same experiment, on the same fusion peak (Reset all coefficients (sensitivity,

temperature) to carry out calibrations) of the metal standard.

2.6.4. Calibration with a single standard

If the transformation takes place within a limited temperature range, a single

coefficient of calibration can be used by choosing the standard with the closest

melting point.

Let H be the fusion heat content for the metal standard chosen (in J / g),

Let m be the mass of the standard analyzed (in g),

Let S be the area of the fusion peak (in µV. s),

Then, the calibration coefficient at the standard’s melting point is given by:



( )KS

Hxm

V W=1

µ / in microvolt per watt

K is better expressed in µV/mW.

For any peak area A (in µV. s) combined with the corresponding transformation Q (in Joule), the formula is:

QA

K=

2.6.5. Calibration with various standards

As mentioned in the previous paragraph, calibration with a single standard is

recommended for a limited temperature range. However, if the test is carried out

over several hundred degrees, various metal standards are recommended so as to

plot a variation curve of the coefficient of calibration as a function of temperature.

The substances shown in paragraph 2.6.2 can be used.

Choose at least five standards in order to produce correct determining.

Let Hi be the fusion heat content of the standard i (in J / g),

Let mi be the mass of the standard i investigated (in grams),

Let Si be the area of the fusion peak (in µV. s),

The coefficient of calibration Ki at the standard’s melting point Teim is given by:

KS

Hxm

i

i

i i

=1 (in µV / W)

Express Ki in µV / mW.

Draw up a table (Teim, Ki) and plot the variation K = f (Teim)

This calibration curve reveals the instrument’s coefficient of calibration at any

temperature (see example hereafter).



-50 0 50 100 150 200 250 300 350 400 4500

températures (°C)

K (microV/mW)

A0 = 3.0908E+00A1 = 7.0250E -03

1

2

3

A2 =-4.5361E -05A3 = 8.8112E -08A4 =-6.0381E -11

FIGURE 36: DSC 131 CALIBRATION CURVE

The coefficients A0, A1, A2, A3, A4 thus determined are entered on to the

software’s Parameter page for automatically transforming the DSC signal into thermal power.

The peak integration directly supplies the transformation heat in Joules.

DSC 131 – Annex A

Appendix A 52 G/DSC131-1A – 07/07/06

APPENDIX A

Reference Material Transition T (K) T (°C) Uncertainty (mK) Ref * CRM Remarks ** Cyclopentane s/s 122.38 -150.77 50 1 a Cyclopentane s/s 138.06 -135.09 50 1 a Cyclopentane s/l 179.72 -93.43 50 1 a Cyclohexane s/s 186.24 -86.91 20 2 a Mercury s/l 234.29 -38.86 30 3 NIST SRM 2225 n-Decane s/l 243.51 -29.64 4 a Water s/l 273.15 0.00 10 1 b Gallium s/l 302.9146 29.7646 1 c Gallium s/l 302.930 29.780 10 8 PTB c Naphtalene s/l 353.38 80.23 20 5 LGC 2603 a Potassium nitrate s/s 401 128 5000 6 Indium s/l 429.7485 156.5985 46 3 NIST SRM 2232 Tin s/l 505.09 231.94 10 3 NIST SRM 2220 d Tin s/l 505.078 231.928 1 d Bismuth s/l 544.550 271.400 10 8 PTB c Lead s/l 600.62 327.47 20 5 LGC 2608 e Lead s/l 600.61 327.46 10 1 e Zinc s/l 692.677 419.527 1 f Zinc s/l 692.71 419.56 20 3 NIST SRM 2221A f Silver sulfate s/s 697 424 5000 6 Silver sulfate s/s 697 424 3 NIST SRM 8759 Quartz s/s 844 571 5000 6 g Quartz s/s 844 571 3 NIST SRM 8759 g Lithium Sulphate s/s 851.43 578.28 250 1 h Aluminium s/l 933.48 660.33 50 5 LGC 2612 i Silver s/l 1234.930 961.780 2 3 NIST SRM 1746 j Gold s/l 1337.33 1064.18 1 j Nickel s/l 1728 1455 7 k Palladium s/l 1827 1554 7 k Alumina s/l 2325 2052 5000 3 NIST SRM 742

STANDARD REFERENCE MATERIALS FOR TEMPERATURE CALIBRATION ENR7-6ET01

REV.B Page 1 / 1

*References

1. H.K. Cammenga, W. Eysel, E. Gmelin, W. Hemminger, G.W.H. Höhne and S.M. Sarge

The temperature calibration of scanning calorimeters. Part. 2. Calibration substances

Thermochemica Acta, 219 (1993) 333-342

2. R. Sabbah, An Xu-wu, J.S. Chickos, M.L. Planas Leitao, M.V. Roux, L.A. Torres

Reference materials for calorimetry and differential thermal analysis

Thermochimica Acta 331 (1999) 93-204

3. Values from National Institute of Standards and Technology (NIST).[USA]

4. Finke H.L. ; Gross M.E. ; Waddington G. ; Huffman H.M.

Low temperature thermal data for the nine normal paraffin hydrocarbons from octane to hexadecane

Journal of the American Chemical Society, 1954, 76, 333-341

5. Values from the Laboratory of the Governement Chemist (LGC).[UK]

Handbook of Thermal Analysis and Calorimetry, Patrick K. Gallagher, Volume 1 – Principles and Practise, 1998

Chap 13 – Calibration and Standardisation in DSC-M.J. Richardson and E.L. Charsley

6. Norme ASTM E967-97 Standard Practice for Temperature Calibration of DSC and DTA

(F.D. Rossini, pure applied chemistry, Vol 22, 1970, p 557)

7. Values from the Physikalisch-Technische Bundesanstalt (PTB).[Germany]

**Remarks

a. Only in hermetically sealed crucible.

b. Air-satured, bidistilled water in hermetically closed crucible.

c. Melt reacts with Al (strong supercooling with Gallium).

d. Melt reacts with Al, Pt.

e. Melt reacts with Pt, oxidizes quickly (use protective gas).

f. Melt (and vapour) react with Al, Pt ; high vapour pressure at melting point (approx 20 Pa).

g. Use metallic crucible only.

h. Anhydrate is hygroscopic, thus weigh-in as Li2SO4.H2O, Dehydratation takes place from 100° C, thus turbulent movement of particles in the crucible and high water-vapour pressure (do not use hermetically sealed crucible), Must not melt (change of

properties).

i. Melt reacts strongly with Pt.

j. Melt dissolves oxygen, reacts with Pt.

k. Use Al2O3 crucible only

DSC 131 – Annex B

Appendix B 53 G/DSC131-1A – 07/07/06

APPENDIX B

Reference Material Transition T (°C) Heat (J/g) Uncertainty (J/g) Ref * CRM Remarks **

Cyclopentane s/s -150.77 69.60 ±0.35 1 a Cyclopentane s/s -135.09 4.91 ±0.03 1 a Cyclopentane s/l -93.43 8.63 ±0.05 1 a Cyclohexane s/s -86.91 79.8 ±0.9 2 a Mercury s/l -38.86 11.469 ±0.008 3 NIST SRM 2225 Water s/l 0.00 333.78 4 b Gallium s/l 29.7646 79.88 ±0.72 1 c Gallium s/l 29.780 80.14 ±0.33 5 PTB c Naphtalene s/l 80.23 147.6 ±0.7 6 LGC 2603 a Potassium nitrate s/s 128 50.5 7 Indium s/l 156.5985 28.51 ±0.19 3 NIST SRM 2232 Tin s/l 231.94 60.21 ±0.19 3 NIST SRM 2220 d Bismuth s/l 271.400 53.14 ±0.22 5 PTB c Lead s/l 327.47 23.00 ±0.06 6 LGC 2608 e Zinc s/l 419.56 107.4 ±1.3 3 NIST SRM 2221A f Lithium Sulphate s/s 578.28 228.1 ±10.5 1 g Aluminium s/l 660.33 401.3 ±1.6 6 LGC 2612 h Silver s/l 961.780 104.8 8 i Gold s/l 1064.18 64.5 1 i Nickel s/l 1455 300 7 j Palladium s/l 1554 162 7 j Alumina s/l 2052 1092 9

STANDARD REFERENCE MATERIALS FOR

HEAT CALIBRATION ENR7-6ET03

REV. A Page 1 / 1

* References

1. S.M. Sarge, E. Gmelin, G.H. Höhne, H.K. Cammenga, W. Hemminger, W. Eysel.

The caloric calibration of scanning calorimeters.

Thermochemica Acta 247 (1994) 129-168.

2. R. Sabbah, An Xu-wu, J.S. Chickos, M.L. Planas Leitao, M.V. Roux, L.A. Torres

Reference materials for calorimetry and differential thermal analysis

Thermochimica Acta 331 (1999) 93-204

3. Values from National Institute of Standards and Technology (NIST).[USA]

4. DSC Calibration below 0°C, G. Hakvoort, Journal of Thermal Analysis, vol 41 (1994)1551-1555.

5. Values from the Physikalisch-Technische Bundesanstalt (PTB);[Germany}]

6. Values from the Laboratory of the Governement Chemist (LGC).[UK]

7. Handbook of Thermal Analysis and Calorimetry, Patrick K. Gallagher, Volume 1 – Principles and Practise, 1998

Chap 13 – Calibration and Standardisation in DSC-M.J. Richardson and E.L. Charsley

8. J. Emsley, The elements, 3rd edition, Oxford Press, Oxford 1998.

9. Handbook of Chemistry and Physics, 83rd edition, D.R. Lide, CRC Press 2002-03.

**Remarks

a. Only in hermetically sealed crucible.

b. Air-satured, bidistilled water in hermetically closed crucible.

c. Melt reacts with Al (strong supercooling with Gallium).

d. Melt reacts with Al, Pt.

e. Melt reacts with Pt, oxidizes quickly (use protective gas).

f. Melt (and vapor) react with Al, Pt ; high vapor pressure at melting point (approx 20 Pa).

g. Anhydrate is hygroscopic, thus weigh-in as Li2SO4.H2O, Dehydratation takes place from 100° C, thus turbulent movement of particles

in the crucible and high water-vapor pressure (do not use hermetically sealed crucible), Must not melt (change of properties).

h. Melt reacts strongly with Pt.

i. Melt dissolves oxygen, reacts with Pt.

j. Use Al2O3 crucible only

DSC 131 – Annex C

Appendix C 54 G/DSC131-1A – 07/07/06

APPENDIX C Compatibility of reference substances / crucibles materials

According to H.K. Commenga et al, The temperature Calibration of scanning calorimeters.

Part2: Calibration substances, Thermochimica acta, 219 (1993), 333-342

Calibration substance

Crucible material cycl

open

tane

wat

er

Gal

lium

Indi

um

Tin

Lead

Zin

c

Lith

ium

sul

phat

e

Alu

min

ium

Silv

er

Gol

d

Corundum, Al2O3 0 0 + + + + + + + + + Boron Nitride, BN 0 0 + + + + + + + ? ? Graphite, C 0 0 + + + + + + + + - Silicate glass + + + + + + ? + - ×××× ×××× Quartz glass, SiO2 + + + + + + + + - + + Aluminium + •••• - + - + - + ×××× ×××× ×××× Aluminium oxidized + + + + + + + + ×××× ×××× ×××× silver, Ag + + - - - - - ? - ×××× ×××× Gold, Au + + •••• •••• - - - + - - ×××× Nickel, Ni + + •••• •••• •••• •••• •••• ? - + - Iron, Fe + •••• •••• + •••• + - ? - + - Stainless steel + + •••• + •••• + - ? - + - Platinum, Pt + + •••• •••• - - - + - - - Molybdenum, Mo + + •••• ? •••• ? •••• ? ? ? - Tantalum, Ta + + ? + ? ? ? + - + - Tungsten, W 0 0 •••• ? ? •••• + ? •••• + +

0 hermetic sealing of crucible not easily possible.

+ no solubility and no influence on the melting temperature to be expected.

- melt dissolves crucible material, greater change in the melting temperature.

• partial solution processes are possible with negligible change in the melting temperature. × crucible melts. ? compatibility unknown.

DSC 131 – Annex D

Appendix D 54 G/DSC131-1A – 07/07/06

ANNEX D

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