SIST EN 1159-3:2004
(Main)Advanced technical ceramics - Ceramic composites, thermophysical properties - Part 3: Determination of specific heat capacity
Advanced technical ceramics - Ceramic composites, thermophysical properties - Part 3: Determination of specific heat capacity
This part of EN 1159 describes two methods for the determination of the specific heat capacity of ceramic matrix composites with continuous reinforcements (1D, 2D, 3D). The two methods are: - Method A: Drop calorimetry; - Method B: Differential scanning calorimetry. They are applicable from ambient temperature up to a maximum temperature depending on the method: method A may be used up to 2 250 K, while method B is limited to 1 900 K.
Hochleistungskeramik - Keramische Verbundwerkstoffe, thermophisikalische Eigenschaften - Teil 3: Bestimmung der spezifischen Wärmekapazität
Dieser Teil der prEN 1159 beschreibt zwei Verfahren zur Bestimmung der spezifischen Wärmekapazität von keramischen Verbundwerkstoffen mit Endlos-Faserverstärkung (1D, 2D, 3D). Die beiden Verfahren sind: - Verfahren A: Tropfenkalorimetrie; - Verfahren B: Dynamische Differenz-Kalorimetrie (DDK). Die Verfahren sind vonRaumtemperatur bis zu einer Maximaltemperatur anwendbar, wobei die Temperaturen verfahrensabhängig sind; Verfahren A kann bis 2 250 K angewendet werden, während Verfahren B auf Temperaturen bis zu 1 900 K beschränkt ist.
Céramiques techniques avancées - Composites céramiques, propriétés thermophysiques - Partie 3: Détermination de la capacité thermique spécifique
Cette partie de l'EN 1159 décrit deux méthodes pour la détermination de la capacité thermique spécifique des composites a matrice céramique a renforts continus (1D, 2D, 3D).
Les matrices sont a renforts unidirectionnels (1D), bidirectionnels (2D) et tridirectionnels (XD, avec 2 3).
Les deux méthodes sont :
méthode A : calorimétrie a chute ;
méthode B : calorimétrie différentielle a balayage.
Elles sont applicables depuis la température ambiante jusqu'a une température maximale qui dépend de la méthode : la méthode A peut etre utilisée jusqu'a 2 250 K, tandis que la méthode B est limitée a 1 900 K.
NOTE La méthode A se limite a la détermination d'une valeur moyenne de la capacité thermique spécifique dans un intervalle de température donné et peut conduire a une dispersion importante des résultats.
Advanced technical ceramics - Ceramic composites, thermophysical properties - Part 3: Determination of specific heat capacity
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Advanced technical ceramics - Ceramic composites, thermophysical properties - Part 3: Determination of specific heat capacityHochleistungskeramik - Keramische Verbundwerkstoffe, thermophisikalische Eigenschaften - Teil 3: Bestimmung der spezifischen WärmekapazitätCéramiques techniques avancées - Composites céramiques, propriétés thermophysiques - Partie 3: Détermination de la capacité thermique spécifiqueAdvanced technical ceramics - Ceramic composites, thermophysical properties - Part 3: Determination of specific heat capacity81.060.30Sodobna keramikaAdvanced ceramicsICS:Ta slovenski standard je istoveten z:EN 1159-3:2003SIST EN 1159-3:2004en01-januar-2004SIST EN 1159-3:2004SLOVENSKI
STANDARDSIST ENV 1159-3:20001DGRPHãþD
SIST EN 1159-3:2004
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 1159-3April 2003ICS 81.060.20Supersedes ENV 1159-3:1995English versionAdvanced technical ceramics - Ceramic composites,thermophysical properties - Part 3: Determination of specificheat capacityCéramiques techniques avancées - Compositescéramiques, propriétés thermophysiques - Partie 3:Détermination de la capacité thermique spécifiqueHochleistungskeramik - Keramische Verbundwerkstoffe,thermophisikalische Eigenschaften - Teil 3: Bestimmungder spezifischen WärmekapazitätThis European Standard was approved by CEN on 2 January 2003.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and UnitedKingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2003 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 1159-3:2003 ESIST EN 1159-3:2004
EN 1159-3:2003 (E)2ContentspageForeword.31Scope.42Normative references.43Terms and definitions.44Method A - Drop calorimetry.54.1Principle.54.2Apparatus.54.3Standard reference materials.54.4Test specimens.54.5Calibration of calorimeter.54.5.1General.54.5.2Electrical Calibration.64.5.3Calibration using standard reference material.64.6Test procedures.64.6.1Test without a crucible.64.6.2Test with a crucible.64.6.3Description of test.74.7Calculations.74.7.1General.74.7.2Determination of the calorimetric calibration factor.84.7.3Determination of mean specific heat capacity pC.85Method B - Differential scanning calorimetry.95.1Principle.95.1.1General.95.1.2Stepwise heating method.95.1.3Continuous heating method.95.2Apparatus.105.2.1Differential scanning calorimeter.105.3Standard reference materials, SRM.105.4Test specimens.105.5Temperature calibration.105.6Test procedure for the determination of Cp.115.6.1General.115.6.2Method 1: Measurements requiring the knowledge of the K factor.115.6.3Method 2: Measurements requiring the use of a reference standard material (SRM).125.7Calculation of results.135.7.1Method requiring the knowledge of the K factor.135.7.2Method using an SRM.146Test report.16Annex A (normative)
Drop calorimetry - Determination of the calibration factor using standardreference material.19Annex B (informative)
Standard reference material.20Annex C (informative)
Materials for calorimeter calibrations.25Bibliography.26SIST EN 1159-3:2004
EN 1159-3:2003 (E)3ForewordThis document (EN 1159-3:2003) has been prepared by Technical Committee CEN/TC 184 "Advanced technicalceramics", the secretariat of which is held by BSI.This European Standard shall be given the status of a national standard, either by publication of an identical text orby endorsement, at the latest by October 2003, and conflicting national standards shall be withdrawn at the latestby October 2003.This document supersedes ENV 1159-3:1995.EN 1159 Advanced technical ceramics – Ceramic composites, thermophysical properties consists of three parts:¾ Part 1: Determination of thermal expansion¾ Part 2: Determination of thermal diffusivity¾ Part 3: Determination of specific heat capacityAnnex A is normative. Annexes B and C are informative.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,Slovakia, Spain, Sweden, Switzerland and the United Kingdom.SIST EN 1159-3:2004
EN 1159-3:2003 (E)41 ScopeThis part of EN 1159 describes two methods for the determination of the specific heat capacity of ceramic matrixcomposites with continuous reinforcements (1D, 2D, 3D).Unidirectional (1D), bi-directional (2D) and tridirectional (XD, with 2 < x £ 3).The two methods are:¾ method A: drop calorimetry;¾ method B: differential scanning calorimetry.They are applicable from ambient temperature up to a maximum temperature depending on the method: method Amay be used up to 2 250 K, while method B is limited to 1 900 K.NOTEMethod A is limited to the determination of an average value of the specific heat capacity over a given temperaturerange and can give a larger spread of results.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN 60584-1, Thermocouples - Part 1: Reference tables (IEC 60584-1:1995).ENV 13233:1998, Advanced technical ceramics – Ceramic composites – Notations and symbols.3 Terms and definitionsFor the purposes of this European Standard, the following definitions and those given in ENV 13233:1998 apply.3.1specific heat capacity, Cpamount of heat required to raise the temperature of a mass unit of material by 1 K at constant temperature andpressuredTdQmCp1=whereQis the heat required for a test-piece of mass m3.2mean specific heat capacity, pCamount of heat required to raise the temperature of a mass unit of a material from temperature T1 to temperatureT2 at a constant pressure, divided by the temperature range (T2 – T1) expressed in K3.3representative volume element (R.V.E.)the minimum volume which is representative of the material consideredSIST EN 1159-3:2004
EN 1159-3:2003 (E)54 Method A - Drop calorimetry4.1 PrincipleA test piece is dropped from a conditioning chamber at a constant temperature T1 to another chamber at a constanttemperature T2.The mean specific heat capacity is determined from the measured amount of heat required to maintain thetemperature constant in the second chamber. Transfer of the test piece shall be done under conditions as close aspossible to adiabatic conditions.4.2 Apparatus4.2.1Drop calorimeter, there are several types of drop calorimeters. They include one (or more) conditioningchambers and measuring chambers which can be operated under controlled atmosphere and which are allequipped with a temperature control system which allows a temperature stability of less than 1 K.The conditioning chamber shall have a homogeneous temperature zone size greater than the test specimen size.The measuring chamber shall have a homogeneous temperature zone of a sufficient length to accept severalspecimens and a sufficient thermal inertia to limit the temperature disturbance, due to the drop.Heat transfer by radiation during the drop shall be avoided as far as possible.4.2.2Balance, with an accuracy of 0,1 mg for test pieces over 10 mg and an accuracy of 0,01 mg for test piecesbelow 10 mg.4.2.3Temperature detectors, thermocouples in accordance to EN 60584-1 shall be used for the measurementof temperature up to 1 920 K.For higher temperature, infrared detectors or any other suitable device may be used.4.2.4Data acquisition system, the sampling period during the test shall be less than 0,5 s.4.3 Standard reference materialsStandard reference materials which can be used for calibration purposes are listed in annex B.4.4 Test specimensThe test specimens shall be representative of the material.NOTEThis criterion is generally met by test specimens containing the maximum number of representative volumeelements, compatible with the volume of the crucible, if this number is less than five, several solutions are possible:a) the test specimens should have an exact number of representative volume elements;b) the material should be ground to powder and a specimen taken from this powder. However this solution willlead to results which may differ from results obtained on solid test pieces and should be used only if no othersolution is possible;c) the material should be cut into specimens and a number of similar test specimens should be tested and anaverage value determined.4.5 Calibration of calorimeter4.5.1 GeneralCalibration of calorimeters, may be done according to two different methods. The first consists in dissipating aknown amount of thermal power using a calibrated resistor introduced in the second chamber of the calorimeter. InSIST EN 1159-3:2004
EN 1159-3:2003 (E)6the second method a reference specimen with known specific heat capacity is dropped according to the proceduredescribed in section 4.6.4.5.2 Electrical CalibrationThe calibration factor is the ratio of a known amount of thermal power dissipated in the resistor to the steady statecalorimetric output signal and is measured at temperature T2.NOTE 1The method using power dissipation in a resistor is limited to 1 350 K.NOTE 2This method can only be used if the sensitivity of the calorimeter is not affected by the filling of the measuringchamber.4.5.3 Calibration using standard reference materialThis calibration is called “drop calibration”. A specimen made from a standard reference material with a knownspecific heat capacity is dropped according to the test procedures described in section 4.6. (See annex B forstandard reference material). This allows determination of the calibration factor (see annex A).4.6 Test proceduresNOTEThe avoidance of interaction between the test specimen and the calorimetric conditioning and measuring chamberscan require the use of a sealed crucible.4.6.1 Test without a crucible4.6.1.1 Test with drop calibrationThe test without a crucible and with drop calibration is done in the following order:R, T, R, T, R, T, RwithR = test of standard reference material, and;T = test of test specimen.Carry out each test as described in 4.6.3.4.6.1.2 Test with electrical calibrationThe test without a crucible and with calibration using power dissipation in a resistor is done in the following order:¾ calibration of calorimeter;¾ test on three test specimens.Carry out each test as described in 4.6.3.4.6.2 Test with a crucible4.6.2.1 GeneralThe mass of all empty crucibles used for the test shall not differ by more than 5 %.4.6.2.2 Test with drop calibrationThe test with a crucible and with drop calibration is carried out in the following order:SIST EN 1159-3:2004
EN 1159-3:2003 (E)7C, C + R, C + T, C, C + R, C + T, C, C + R, C + T, CwithCis the test with the empty crucible;C + R = test of crucible plus standard reference material;C + T = test of crucible plus test specimen.Carry out each test as described in 4.6.3.4.6.2.3 Test with electrical calibrationThe test with a crucible and with calibration using power dissipation in a resistor is done in the following order:¾ calibration of calorimeter;¾ carry out the following sequence:C, C + T, C, C + T, C, C + T, CwithCis the test with the empty crucible;C + T = test with crucible plus test specimen.Carry out each test as described in 4.6.3.4.6.3 Description of testThe test piece (test specimen, standard material or empty crucible) and reference material shall be dried at(110 ± 5) °C until the difference in weight of two successive weighings is lower than 0,2 mg:¾ measure the mass when a crucible is not used with an accuracy of ± 0,1 mg or ± 0,1 % whichever is thesmaller;¾ when a crucible is used, measure the mass of each assembly dropped, (empty crucible, crucible and standardreference material, crucible and test specimen);¾ place the test piece (test specimen, standard material or empty crucible) in the conditioning chamber attemperature T1 and wait for a sufficient period (in the order of 15 min), to reach thermal equilibrium of the testpiece with its environment. Measure T1 and T2 start recording the calorimetric signal before the test piece isdropped. Drop the test piece. Stop the record when the steady state output signal is reached.4.7 Calculations4.7.1 GeneralThe change in heat Q corresponding to the drop of the test piece is related to the area A under the calorimetricoutput signal by the following equation.AKQ×=whereKis the calorimeter calibration factor.SIST EN 1159-3:2004
EN 1159-3:2003 (E)84.7.2 Determination of the calorimetric calibration factor4.7.2.1 Electrical calibration (see annex A)AHK==signal outputic calorimetrtheunderareadissipated heat4.7.2.2 With standard reference materialSee annex B.4.7.3 Determination of mean specific heat capacity pCThe mean specific heat capacity is determined using the following formula:()()),,1221ii21p(1T - TTT Q m = TTCwhereT1is the initial temperature at which test pieces, are conditioned;T2is the calorimeter temperature;Qi (T1,T2)is the heat variation between T1 and T2;miis the mass of the test piece, determined by weighing;()21pT,T Cmean specific heat capacity between T1 and T2.The subscript i has a different meaning depending on the type of test piece:¾ i = c for an empty
crucible;¾ i = t for a test piece;¾ i = t + c for a test piece and crucible.without crucible÷÷øöççèæ-·=12TTmAKCttptwith crucible))12tct +c ptT - (T mA - (A K = CwithAtis the value of integration of calorimetric output signal of test specimen;Acis the value of integration of calorimetric output signal of crucible;Ac+tis the value of integration of calorimetric output signal of test specimen plus crucible.SIST EN 1159-3:2004
EN 1159-3:2003 (E)95 Method B - Differential scanning calorimetry5.1 Principle5.1.1 GeneralThe method consists in measuring the difference in power needed to raise the temperature of the test specimen inits crucible and of an empty identical crucible using the same heating programme which may be stepwise heatingor continuous heating.Stepwise heating allows only the determination of the mean specific heat capacity ()21,pTTC over a temperaturerange (T1, T2) while continuous heating allows to determine the specific heat capacity Cp at a given temperature.5.1.2 Stepwise heating methodThe mean specific heat capacity ()21,pTTCis measured in a temperature interval defined by two isothermal levelsT1 and T2. The heat QE which is necessary to change the temperature from T1 to T2 is determined by integratingthe thermal power PE with respect to time. The corresponding heat QE is:()))12oc21ptEE((T - T CC +
T,TC m = dtP = Qto+òwheremtis the mass of the test specimen;()21,pTTCis the mean specific heat capacity of the test specimen;Cois the heat capacity of the calorimeter;Ccis the heat capacity of the crucible.Another experiment for the determination of the base line is performed using an identical imposed heatingsequence with the empty crucible. The corresponding heat QB is given by:[])12ocBBT - (T C + C = dtP = QtoòFrom the above equations the mean specific heat capacity can be calculated as:())12tBE21pT - (T mQ - Q = T-TC5.1.3 Continuous heating methodTemperature is increased linearly versus time at a constant heating rate ß. Using the same notation as in 5.1.2 thethermal power PE supplied at every moment to the system is:()bocpttcCCCmSK++=×+Another experiment for the determination of the base line is performed with the empty crucible. The correspondingthermal power is given byb C + (C = SK)occ×SIST EN 1159-3:2004
EN 1159-3:2003 (E)10The specific heat capacity can be calculated from:()b mSSK = Ctctcp-+withKthe calibration factor and Sc, Sc+t are the output signals, where K × Sc and K × Sc+t are the thermal powerssupplied to the system.5.2 Apparatus5.2.1 Differential scanning calorimeter5.2.1.1There are two types of differential scanning calorimeters operating on power compensation and heatflux principles, both designed to operate under adiabatic conditions.Both comprise two measuring cells housed in a furnace which provides overall system heating. One cell containsthe test specimen and its crucible, the other contains an empty crucible only.5.2.1.2Power compensation type: each cell has an additional heater to compensate for the temperaturevariations from the overall heating programme. The power which is supplied to either cell heater to maintain equaltemperatures during heating is measured.5.2.1.3Heat flux type: power is exchanged between each cell and its respective surrounding, during theheating programme. The difference in power exchange between the two cells is measured.5.2.2Balance, with an accuracy better than 0,1 mg.5.2.3Temperature detectors, thermocouples in accordance with EN 60584-1 shall be used for themeasurement of temperature.5.2.4 Data acquisition system, the time duration between two successive measurements shall be lessthan 0,5 s.5.3 Standard reference materials, SRMStandard reference materials shall be used for calibration. An example is given in annex B.5.4 Test specimensThe test specimens shall be representative of the material.NOTEThis criterion is generally met by test specimens containing the maximum number of representative volumeelements, compatible with the volume of the crucible, if this number is less that 5, several solutions are possible:a) the test specimens should have an exact number of representative volume elements;b) the material should be ground to powder and a specimen taken from this powder. However this solution willlead to results which may differ from results obtained on solid test specimens and should only be used if noother solution is possible;c) the material should be cut into pieces and a number of similar test pieces should be tested and an averagevalue determined.5.5 Temperature calibrationA temperature calibration curve for the furnace using the same heating rate as for the determination of the specificheat capacity is established by using the melting points of standard reference materials (see for example annex C).SIST EN 1159-3:2004
EN 1159-3:2003 (E)11Thermocouples shall be calibrated in accordance with EN 60584-1.5.6 Test procedure for the determination of Cp5.6.1 GeneralDepending on the necessity to use or not a calibration factor K for the calorimeter, two methods can be used:Method 1: measurements requiring the knowledge of the K factor; in that case, care shall be taken in order toensure that the calibration is valid for all the measurements to be done.NOTEGenerally, this can be done by running a test using a test specimen with well-known properties.Method 2: measurements requiring the use of a reference standard material during a series of tests.5.6.2 Method 1: Measurements requiring the knowledge of the K factor5.6.2.1 Determination of the K factorThe calibration factor K is obtained by electrical calibration. It is determined from the ratio of a known amount ofpower dissipated in a resistor to the steady state calorimetric output signal.5.6.2.2 Measurements with the specimen for the determination of the Cp5.6.2.2.1 GeneralA series of measurements shall always be referenced to a base line measurement performed under identicalexperimental conditions as the other measurements in the series. The type of crucible used depends on the type ofthe test specimen and on the temperature range and shall be the same for the series of measurements. The massof all empty crucibles used in the series shall not differ by more than 5 %.5.6.2.2.2 Test sequence for the stepwise heating method (see Figure 1)Generation of the base line:1) weigh the two empty crucibles to the nearest 0,1 mg;2) place the two crucibles in the calorimeter;3) set the calorimeter heating rate, initial and final temperature, and cooling rate;NOTEGenerally the heating rate is in the range 1 K/min to 20 K/min.4) heat to an initial temperature, and wait for the temperature to be stabilised at the initial temperature;5) heat at a constant rate to final temperature of the first step while recording the calorimeter output signaluntil the final temperature is reached and stabilised in order to obtain a base line;6) repeat 3 to 5 for the number of steps required;7) cool down to initial temperature;8) remove the crucibles from the measurement cell.SIST EN 1159-3:2004
EN 1159-3:2003 (E)12Measurements using a test specimenWeigh the test specimen and place it in the crucible to be located in the measurement cell. Repeat operations 2to 8 of the above paragraph on generation of the base line. Repeat this procedure for a minimum of three testspecimens.5.6.2.2.3 Test sequence for the continuous heating method (see Figure 2)Generation of the base line:1)weigh the two empty crucibles to the nearest 0,1 mg;2)place the two crucibles in the calorimeter;3)set the calorimeter heating rate, initial and final temperature, and cooling rate;NOTEGenerally the heating rate is in the range 1 K/min to 20 K/min.4)heat to an initial temperature, and wait for the temperature to be stabilised at the initial temperature;5)heat at a constant rate to final temperature of the first step while recording the calorimeter output signaluntil the final temperature is reached and stabilised in order to obtain a base line;6)cool down to initial temperature;7)remove the crucibles from the measurement cell.Measurements using a test specimenWeigh the test specimen and place it in the crucible to be located in the measurement cell. Repeat operations 2to 7 of the above paragraph on generation of the base line. Repeat this procedure for a minimum of three testspecimens.5.6.3 Method 2: Measurements requiring the use of a reference standard material (SRM)5.6.3.1 GeneralThe two methods described in the following paragraphs 5.6.3.2 and 5.6.3.3 require each:¾ measurements with two empty crucibles for the generation of the baseline;¾ measurements with one empty crucible and one crucible with the SRM;¾ measurements with one empty crucible and one crucible with the test specimen.5.6.3.2 Test sequence for the stepwise heating method (see Figure 3)Generation of the base line1)weigh the two empty crucibles to the nearest 0,1 mg;2)place the two crucibles in the calorimeter;3)set the calorimeter heating rate, initial and final temperature, and cooling rate;NOTEGenerally the heating rate is in the range 1 K/min to 20 K/min.4)heat to an initial temperature, and wait for the temperature to be stabilised at the initial temperature;SIST EN 1159-3:2004
EN 1159-3:2003 (E)135)heat at a constant rate to final temperature of the first step while recording the calorimeter output signaluntil the final temperature is reached and stabilised in order to obtain a base line;6)repeat 3 to 5 for the number of steps required;7)cool down to initial temperature;8)remove the crucibles from the measurement cell.Measurement with a test specimen or with a SRMWeigh the test specimen or the SRM and place it in the crucible to be located in the measurement cell. Repeatoperations 2 to 8 of the above paragraph on generation of the base line. Repeat this procedure for a minimum ofthree test specimens.5.6.3.3 Test sequence for continuous heating method (see Figure 4)Generation of the base line1)weigh the two empty crucibles to the nearest 0,1 mg;2)place the two crucibles in the calorimeter;3)set the calorimeter heatin
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