Designation:D2583–95(Reapproved2001)e1An American National Standard Standard Test Method for
Indentation Hardness of Rigid Plastics by Means of a Barcol Impressor1
This standard is issued under thefixed designation D2583;the number immediately following the designation indicates the year of
original adoption or,in the ca of revision,the year of last revision.A number in parenthes indicates the year of last reapproval.A
superscript epsilon(e)indicates an editorial change since the last revision or reapproval.
This standard has been approved for u by agencies of the Department of Defen.
三倍英语e1N OTE—Editorial changes were made throughout in November2001.
1.Scope
1.1This test method covers the determination of indentation hardness of both reinforced and nonreinforced rigid plastics using a Barcol Impressor,Model No.934-1and Model No. 935.
1.2The values stated in SI units are to be regarded as the standard.The values given in parenthes are for information only.
1.3This standard does not purport to address all of the safety concerns,if any,associated with its u.It is the responsibility of the ur of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to u.
N OTE1—There is currently no ISO standard that duplicates this test method.
2.Referenced Documents
2.1ASTM Standards:
D618Practice for Conditioning Plastics for Testing2
D883Terminology Relating to Plastics2
D4000Classification System for Specifying Plastic Mate-rials3
D4805Terminology for Plastics Standards3
E691Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method4
3.Terminology
3.1Definitions—For definitions of technical terms pertain-ing to plastics ud in this test method,e Terminology D883 or Terminology D4805.
4.Summary of Test Method
4.1A material’s surface hardness is determined through the u of a Barcol Impressor.The relative depth of penetration of the Impressor’s indentor provides a comparative measure of the material’s hardness.The Model No.934–1and Model No. 935Barcol Impressors are designated for u.Within t
he range of hardness measured by the Impressors the Model No. 934-1is ud for measuring harder materials and the Model No.935is ud for measuring softer materials.
5.Significance and U
5.1The Barcol Impressor is portable and therefore suitable for testing the hardness of fabricated parts and individual test specimens for production control purpos.
5.2Before proceeding with this test method,reference should be made to the specification of the material being tested. Any test specimen preparation,conditioning,dimensions,or testing parameters or combination thereof covered in the materials specification shall take precedence over tho men-tioned in this test method.If there are no material specifica-tions,then the default conditions apply.Table1of Classifica-tion System D4000lists the ASTM materials standards that currently exist.
6.Apparatus(Fig.1and Fig.2)
6.1Indentor5—The indentor shall consist of a hardened steel truncated cone having an angle of26°with aflat tip of 0.157mm(0.0062in.)in diameter.It shallfit into a hollow spindle and be held down by a spring-loaded plunger.See Fig. 2.
6.2Indicating Device—The indicating dial shall have100 divisions,each reprenting a depth of0.0076-mm(0.0003-in.) penetration.The higher the reading the harder the material.
6.3Calibration Standards—“Hard”and“soft”aluminum alloy disks supplied by the manufacturer of the instrument. Other disks should not be ud,even if they are of the same alloy and temper as the manufacturer’s disks,as the hardness of aluminum may vary within any given alloy-temper param-eter.
1This test method is under the jurisdiction of ASTM Committee D20on Plastics and is the direct responsibility of Subcommittee D20.10on Mechanical Properties.
Current edition approved October10,1995.Published December1995.Origi-nally published as D2583–67.Last previous edition D2583–93.
2Annual Book of ASTM Standards,V ol08.01.
3Annual Book of ASTM Standards,V ol08.03. 4Annual Book of ASTM Standards,V ol14.02.
5Apparatus is available from Eurotherm/Barber-Colman,741–F Miller Drive, Leesburg,V A20175–8993.
1
Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.
6.4A smooth glass plate is also needed.
7.Test Specimens
7.1The testing area shall be smooth and free from mechani-cal defects.
7.2Dimensions —Test specimens shall be at least 1.5mm (1⁄16in.)thick and large enough to ensure a minimum distance of 3mm (1⁄8in.)in any direction from the indentor point to the edge of the specimen,as well as from test point to test point.8.Preparation and Operation of Apparatus
四年级好词好句大全摘抄
8.1The preparation and operation of Models 934-1and 935are identical.Place the Impressor and the material to be tested (or the calibration disk)on a solidly supported,flat,hard,firm surface such as stone,metal,or ceramic.If softer supporting surfaces are ud,a fally low instrument reading may occur.8.2Set the point sleeve on the surface to be tested.Set the legs on the same surface or on solid material of the same thickness,so that the indentor is perpendicular to the surface being tested.
Grasp the instrument firmly between the legs and point sleeve.Apply a uniform downward force quickly,by
hand,increasing the force on the ca until the dial indication reaches a maximum (Note 3).Take care to avoid sliding or scraping while the indentor is in contact with the surface being tested.Record the maximum reading.
N OTE 2—It is recommended that measurements be made with the Model 934-1Impressor when values above 90are obtained with the Model 935Impressor and that measurements be made with the Model 935Impressor when values less than 20are obtained with the Model No.934-1Impressor.Values below 10using the Model 935Impressor are inexact and should not be reported.
N OTE 3—Drift in readings from the maximum may occur in some materials and can be nonlinear with time.
9.Calibration
9.1With the plunger upper guide backed out until it just engages the spring,place the Impressor on a glass surface and press down until the point is forced all the way back into the lower plunger guide.T
he indicator should now read 100.If it does not,loon the lock-nut and turn the lower plunger guide in or out to obtain a 100reading.Next,read the “hard”aluminum alloy disk supplied by the manufacturer of the Impressor and,if necessary,adjust so that the reading is within the range marked on the disk.Then do the same with the “soft”disk.If the readings cannot be obtained,subquent mea-surements are not valid.
10.Conditioning
10.1Conditioning —Condition the test specimens at 2362°C (73.463.6°F)and 5065%relative humidity for not less than 40h prior to test in accordance with Procedure A of Practice D 618,unless otherwi specified by the contract or relevant material specification.In cas of disagreement,the tolerances shall be 61°C (61.8°F)and 62%relative humid-ity.
10.2Test Conditions —Conduct tests in the standard labora-tory atmosphere of 2362°C (73.463.6°F)and 5065%relative humidity,unless otherwi specified by the contract or relevant material specification.In cas of disagreement,the tolerances shall be 61°C (61.8°F)and 62%relative humid-ity.
11.Procedure
11.1Obrving the precautions of Section 8,make measure-ments on the specimens to be tested (Note 4).Impressions should not be made within 3mm (1⁄8in.)of the edge of the specimen or of other impressions.
N OTE 4—Curved surfaces may be more difficult to support.When the load is applied,bending and spring action in the specimen should be avoided.
12.Number of Readings
12.1Application of the Barcol Impressor to reinforced plastic (nonhomogeneous)materials will produce greater varia-tion in hardness readings than on nonreinforced (homoge-neous)materials.This greater variation may be caud mainly by the difference in hardness between resin and filler materials in contact with the small diameter indentor.There is less variation in hardness readings on harder materials in the range of 50Barcol and higher and considerably more variation in the
TABLE 1Recommended Sample Sizes to Equalize the Variance
因为有了期盼作文of the Average for Model No.934-1
你好吗英文Homogeneous Material
Hardness M-934Scale
Reading Variance Coefficient of Variation,%
Variance
of Average Minimum Number of Readings
20 2.47 2.60.27930 2.20 1.70.28840 1.93 1.30.27750 1.66 1.10.28660 1.390.90.28570 1.120.80.28480
风信子作文
0.85
0.7
0.28
3
Nonhomogeneous Material
(Reinforced Plastics)
铁人王进喜的英雄事迹
3022.4 2.90.77294017.2 2.20.78225012.0 1.70.7516607.8 1.50.781070
3.6
1.2
0.75
5
FIG.1Barcol
Impressor
readings of softer materials.On homogeneous materials,five readings are needed to maintain a variance-of-average of 0.28at a 60Barcol reading;for the same variance-of-average at 30Barcol,eight readings are needed.On reinforced plastics,in order to maintain a variance-of-average of 0.78at 60Barcol,ten readings are needed;and 29readings are needed for the same variance at the 30Barcol level (Table 1).
N OTE 5—The findings were obtained with a round robin conducted in a workshop with all participants prent.Eight plastic materials of different hardness were evaluated with six different Barcol (934-1)Impressors.
13.Report
13.1Report the following information:13.1.1Identification of material tested,13.1.2Conditioning of spe
cimen,13.1.3Model number of Impressor,13.1.4Number of readings taken,
13.1.5Average of hardness values rounded to the nearest whole scale reading,
13.1.6Date of test,and
13.1.7Test method number and published/revision date.14.Precision and Bias
6
14.1No precision statement using Model 935can be offered at this time.
14.2Table 2is bad on a round robin conducted in 1981,in accordance with Practice E 691,involving five materials tested by nine laboratories using Model No.934-1.For each material,all the samples were prepared at one source.Each laboratory obtained three test results for each material.For the materials shown,the indicated number of individual determi-nations were averaged to calculate each test result as follows:
Material
No.of Determinations using Model No.934-1
SAN 8BMC
22SAN reinforced with 20%glass 22Polyester Mat Laminate (thermot)16SMC (sheet molding compound)
16
N OTE 6—Caution:The following explanations of I r and I R (14.3-14.3.3)are only intended to prent a meaningful way of considering the approximate precision of this test method.The data in Table 2should not be rigorously applied to acceptance or rejection of material,as tho data are specific to the round robin and may not be reprentative of other lots,materials,or laboratories.Urs of this test method should apply the principles outlined in Practice E 691to generate data specific to their laboratory and materials,or between specific laboratories.The principles of 14.3-14.3.3would then be valid for such data.
14.3Concept of I r and I R —If S r and S R were calculated from a large enough body of data,and for test results that were averages from the numbers of determinations stated in 14.2:14.3.1Repeatability,I r (Comparing two test results for the same material,obtained by the same operator using the same Barcol Impressor on the same day)—The samples reprented by the two t
虎和龙合不合est results should be regarded as not having equivalent hardness if the test results differed by more than the I r value for that material and condition.
14.3.2Reproducibility,I R (Comparing two test results for the same material,obtained by different operators using differ-ent Barcol Impressors on different days)—The samples repre-nted by the two test results should be regarded as not having
6
Supporting data are available from ASTM Headquarters.Request RR:D20-
1087.
FIG.2Diagram of Barcol Impressor
TABLE 2Precision Data for Model No.934-1
Material
Values in Units of Barcol Hardness
Average S r A S R B I r C I R D SAN 35 1.04 2.9338BMC
390.95 3.75311Reinforced SAN 44 1.11 2.2536Polyester laminate 55 1.45 1.9345SMC
61
1.14
2.15
3
6
A S r =within-laboratory standard deviation of the average.
B
S R =between-laboratories standard deviation of the average.C
I r =2.83S r .D
I R =2.83S R
.
equivalent hardness if the test results differed by more than the
I R value for that material and condition.
14.3.3Any judgment in accordance with14.3.1and14.3.2 would have an approximate95%(0.95)probability of being correct.
14.4Bias—There are no recognized standards on which to ba an estimate of bias for this test method.
15.Keywords
15.1Barcol Hardness Impressor;Models934-1and935; hardness;indentation hardness;rigid plastics
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