thermometer bulb.The capillary tube is not placed in the bath previously,since many materials undergo decomposition upon prolonged heating.Major adjustments of the heat source should be avoided during the actual melting range.
7.4Record the melting range as the temperature range between which liquefactionfirst becomes evident and the temperature at which no further visual change is obrved in the mass.
N OTE1—The initial melting temperature is the temperature at which thefirst actual formation of liquid occurs,either as a minute drop or as a film.It is not a preliminary contraction,sintering,or darkening.It occurs well before the formation of meniscus.The liquefaction may occur at the top,bottom,or sides of the sample in the capillary,as well as the rear. When the latter occurs,the point may be misd,unless care is taken to watch the rear of the tube;a mirror is a convenient aid for this purpo. N OTE2—Thefinal melting temperature is the temperature at which no further liquefaction is obrved.
英语六级阅读技巧
8.Report
8.1Report the results to the nearest division on the ther-mometer,after applying necessary calibration corrections. 9.Precision and Bias
9.1This precision and bias ction has been prepared in accordance with Practice D4483.Refer to this practice for terminology and other statistical details.
9.2The results in this precision and bias ction give an estimate of the precision of the test method with the materials ud in the particular interlaboratory program as described in 9.3.The precision parameters should not be ud for acceptance/rejection testing of any group of materials without documentation that they are applicable to tho particular materials and the specific testing protocols that include this test method.
9.3A Type1interlaboratory precision program was con-ducted.Repeatability is short-term and reproducibility is short-term.Seven laboratories participated and three materials were ud.A test result is the value obtained from one determination. Two determinations were run on each material,and this protocol was repeated on each of three days.The analysis for precision followed the general procedure as t forth in Annex 5of Practice D4483.Each cell of Practice D4483Table1 b
asic data format contained six values(three test days,two test results each day).The estimates for the repeatability param-eters therefore contain two undifferentiated sources of varia-tion,that is,replicates within days and between days.Thefinal precision parameters are given in Table1of this test method.
9.4The results of the precision calculations for the initial melting point and thefinal melting point are arranged in ascending“mean level”order,and given in Table1.
9.5Repeatability—The pooled repeatability,r,of this test method has been established as1.58°C,as given in Table1. Two single test results obtained under normal test method procedures that differ by more than1.58°C must be considered as suspect,that is,having been derived from different or nonidentical sample populations.If this is the ca,appropriate corrective action should be taken.
9.6Reproducibility—The pooled reproducibility,R,of this test method has been established as3.40°C,as given in Table 1.Two single test results obtained under normal test method procedures that differ by more than3.40°C must be considered as suspect,that is,having been derived from different or nonidentical sample populations.If this is the ca,appropriate corrective action should be taken.
9.7Bias—In test method terminology,bias is the difference between an average test value and the reference(or true)test property value.Reference values do not exist for this test method since the value of the melting point is exclusively defined by the test method.Bias,therefore,cannot be deter-mined.
METHOD B—DIFFERENTIAL SCANNING
CALORIMETRY
10.Apparatus
10.1Differential Scanning Calorimeter,capable of heating
a test specimen and a reference material at a controlled rate and of automatically recording the differential heatflow between the samples and the reference material to the required nsi-tivity and precision.
10.2Specimen Pans,compod of aluminum or other metal of high thermal conductivity.The specimen pans must not react with the sample and must not melt under the temperatures of the test.
10.3Nitrogen,or other inert purge gas supply.
10.4Analytical Balance,with a capacity greater than20mg, capable of weighing to the nearest0.01mg.
11.Calibration
11.1Using the same heating rate,purge gas,andflow rate to be ud for the specimen,calibrate the temperature axis of the instrument using the procedure in Practice E967.
exchange是什么意思12.Procedure
12.1Weigh about10to20mg of the sieved specimen into
a DSC specimen pan.Cover and al the specimen pan and place into the DSC sample holder.
12.2Place an empty aled pan into the reference sample holder.
12.3Clo the sample chamber and ensure that the purge gasflow matches that ud for the calibration.
TABLE1ASTM Test Method Precision—Type1:Test Method
D1519Capillary Melting Range
N OTE1—This is short-term precision(days).
N OTE2—The are the same chemicals ud for the DSC.
keep on
Material
Mean
Level,
°C
Within Laboratories A Between Laboratories A
Sr r(r)SR R(R) Initial A47.30.681 1.91 4.02 1.07 3.00 6.34 Initial B98.80.491 1.38 1.39 1.26 3.52 3.57 Initial C176.40.671 1.88 1.07 1.25 3.49 1.98 Final A49.40.376 1.05 2.130.55 1.53 3.10 Final B101.40.426 1.19 1.18 1.43 3.99 3.94 Final C179.70.663 1.86 1.03 1.50 4.19 2.33 Pooled0.565 1.58 1.80 1.22 3.40 3.54
A Sr5within laboratory,standard deviation.
r5repeatability in measurement units.
bellefontaine(r)5repeatability(in percent).
SR5between laboratory,standard deviation.
R5reproducibility in measurement units.
(R)5reproducibility(in
percent).
12.4Heat the specimen rapidly to 50°C below the meltingmsci是什么意思
temperature and allow to equilibrate.
12.5Heat the specimen through the endotherm until ba-
line is re-established above the melting endotherm.Heating
rate must be the same as that ud for the calibration of the
instrument.Ten degrees celsius is a commonly ud rate.
Record the accompanying thermal curve.
12.6Reweigh the specimen after completion of scanning,
and discard.Report any mass loss obrved.
N OTE 3—Mass loss is only one indication of suspected sample degra-
dation or decomposition.Other decomposition indicators,such as color
change,may be noted if the specimen pan is opened.
12.7From the resultant curve,measure the temperatures for
the desired points on the curve,T e ,T p (e Fig.1)to the
required precision,
独立宣言英文where:T e 5extrapolated ont temperature for fusion,°C,and T p 5melting peak temperature,°C.
13.Report
13.1Report T e and T p ,as well as heating rate ud.
13.2Any side reaction (for example,thermal degradation or
oxidation)also should be reported and the reaction identified,
if possible.
14.Precision and Bias
14.1This precision and bias ction has been prepared in
accordance with Practice D 4483.Refer to this practice forwinter in my heart
terminology and other statistical details.
14.2The results in this precision and bias ction give an
estimate of the precision of the test method with the materials
ud in the particular interlaboratory program as described in 14.3.The precision parameters should not be ud for acceptance/rejection testing of any group of materials without documentation that they are applicable to tho particular materials and the specific testing protocols that include this test method.14.3A Type 1interlaboratory precision program was con-ducted.Repeatability is short-term and reproducibility is short-term.Eleven laboratories participated and three materials were ud.A test result is the value obtained from one determination.Two determinations were run on each material,and this protocol was repeated on each of three days.The analysis for precision followed the general procedure as t forth in Annex 5of Practice D 4483.Each cell of Practice D 4483Table 1basic data format contained six values (three test days,two test results each day).The estimates for the repeatability param-eters therefore contain two undifferentiated sources of varia-tion,that is,replicates within days and between days.The final precision parameters are given in Table 2of this test method.14.4The results of the precision calculations for the ont and the peak ar
e arranged in ascending “mean level”order,and given in Table 2.14.5Repeatability —The pooled repeatability,r ,of this test method has been established as 1.40°C,as given in Table 2.Two single test results obtained under normal test method procedures that differ by more than 1.40°C must be considered as suspect,that is,having been derived from different or nonidentical sample populations.If this is the ca,appropriate corrective action should be taken.14.6Reproducibility —The pooled reproducibility,R ,of this test method has been established as 3.75°C,as given in Table 2.Two single test results obtained under normal test method procedures that differ by more than 3.75°C must be considered as suspect,that is,having been derived from different or nonidentical sample populations.If this is the ca,appropriate
my day 英语作文corrective action should be
taken.
FIG.1Sample Melting
Endotherm
14.7Bias —In test method terminology,bias is the differ-
ence between an average test value and the reference (or true)
leggingstest property value.Reference values do not exist for this test method since the value of the melting point is exclusively defined by the test method.Bias,therefore,cannot be deter-mined.15.Keywords 15.1capillary;DSC;melting range;rubber chemicals The American Society for Testing and Materials takes no position respecting the validity of any patent rights asrted in connection with any item mentioned in this standard.Urs of this standard are expressly advid that determination of the validity of any such patent rights,and the risk of infringement of such rights,are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revid,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standards and should be addresd to ASTM Headquarters.Your comments will receive careful consideration at a meeting of the responsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards,10
0Barr Harbor Drive,West Conshohocken,PA 19428.TABLE 2ASTM Test Method Precision—Type 1:Test Method
D 1519DSC
N OTE 1—This is short-term precision (days).
N OTE 2—The are the same chemicals ud for the DSC.
Material
Mean Level,°C Within Laboratories A Between Laboratories A Sr r (r )SR R (R )Ont A
47.00.575 1.61 3.43 1.90 5.3111.30Ont B
99.00.469 1.31 1.33 1.24 3.46 3.50Ont C
176.80.376 1.050.59 1.15 3.21 1.82Peak Armvb是什么意思
50.70.682 1.91 3.77 2.15 6.0211.88Peak B
102.40.445 1.25 1.22 1.20 3.37 3.29Peak C
180.90.370 1.040.57 1.37 3.84 2.12Pooled
0.499 1.40 1.82 1.34 3.75 5.65A Sr
5within laboratory,standard deviation.r
5repeatability in measurement units.(r)
5repeatability (in percent).SR
5between laboratory,standard deviation.R
5reproducibility in measurement units.(R)5reproducibility (in
percent).
