1、September 2016 English price group 14No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 83.060!%Zsu“2558082www.din.deD
2、IN ISO 48Rubber, vulcanized or thermoplastic Determination of hardness (hardness between 10 IRHD and 100 IRHD) (ISO 48:2010),English translation of DIN ISO 48:2016-09Elastomere oder thermoplastische Elastomere Bestimmung der Hrte (Hrte zwischen 10 IRHD und 100 IRHD) (ISO 48:2010),Englische bersetzun
3、g von DIN ISO 48:2016-09Caoutchouc vulcanis ou thermoplastique Dtermination de la duret (duret comprise entre 10 DIDC et 100 DIDC) (ISO 48:2010),Traduction anglaise de DIN ISO 48:2016-09SupersedesDIN ISO 48:2009-10www.beuth.deDocument comprises 28 pagesDTranslation by DIN-Sprachendienst.In case of d
4、oubt, the German-language original shall be considered authoritative.08.16 A comma is used as the decimal marker. Contents Page National foreword . 3 National Annex NA (informative) Bibliography . 4 Introduction. 5 1 Scope . 6 2 Normative references 7 3 Terms and definitions . 7 4 Principle. 8 5 App
5、aratus 8 5.1 General . 8 5.2 Methods N, H, L and M . 8 5.3 Methods CN, CH, CL and CM 10 6 Test pieces 10 6.1 General 10 6.2 Methods N, H, L and M . 11 6.3 Methods CN, CH, CL and CM . 12 7 Time interval between vulcanization and testing 12 8 Conditioning of test pieces 12 9 Temperature of test 12 10
6、Procedure 12 11 Number of readings. . 13 12 Expression of results . 13 13 Precision 13 14 Test report 16 Annex A (informative) Empirical relationship between indentation and hardness. 17 Annex B (informative) Precision results from interlaboratory test programmes 19 Annex C (informative) Guidance fo
7、r using precision results 27 Bibliography 28 DIN ISO 48:2016-092 National foreword This standard (ISO 48:2010) has been prepared by Technical Committee ISO/TC 45 “Rubber and rubber products” (Secretariat: DSM, Malaysia). The responsible German body involved in its preparation was DIN-Normenausschuss
8、 Materialprfung (DIN Standards Committee Materials Testing), Working Committee NA 062-04-34 AA Prfung der physikalischen Eigenschaften von Kautschuk und Elastomeren. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. DIN and/or DKE s
9、hall not be held responsible for identifying any or all such patent rights. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 7619-1 DIN ISO 7619-1 ISO 7619-2 DIN ISO 7619-2 ISO 7743 DIN ISO 7743 ISO 18898 DIN ISO 18898 ISO 23529 DIN ISO
10、23529 Amendments This standard differs from DIN ISO 48:2009-10 as follows: a) in methods N, H and L, the standard test piece can comprise more than one layer; b) precision results obtained in 2007 have been included in Annex B. Previous editions DIN 53503: 1952-01 DIN 53503-1 = DVM 3503-1: 1938-06 D
11、IN 53503-1: 1948-08 DIN 53519: 1965-01 DIN 53519-1: 1972-05 DIN 53519-2: 1972-05 DIN 53529-1: 1971-02, 1983-03 DIN ISO 48: 2003-07, 2009-10 DIN ISO 48:2016-093 National Annex NA (informative) Bibliography DIN ISO 7619-1, Rubber, vulcanized or thermoplastic Determination of indentation hardness Part
12、1: Durometer method (Shore hardness) DIN ISO 7619-2, Rubber, vulcanized or thermoplastic Determination of indentation hardness Part 2: IRHD pocket meter method DIN ISO 7743, Rubber, vulcanized or thermoplastic Determination of compression stress-strain properties DIN ISO 18898, Rubber Calibration an
13、d verification of hardness testers DIN ISO 23529, Rubber General procedures for preparing and conditioning test pieces for physical test methods DIN ISO 48:2016-094 Introduction The hardness test specified in this International Standard is intended to provide a rapid measurement of rubber stiffness,
14、 unlike hardness tests on other materials which measure resistance to permanent deformation. Hardness is measured from the depth of indentation of a spherical indentor, under a specified force, into a rubber test piece. An empirical relationship between depth of indentation and Youngs modulus for a
15、perfectly elastic isotropic material has been used to derive a hardness scale which can conveniently be used for most rubbers. When it is required to determine the value of Youngs modulus itself, it is expected that an appropriate test method be used, for example that described in ISO 7743. The guid
16、e to hardness testing, ISO 18517, can also be a useful reference. DIN ISO 48:2016-095Rubber, vulcanized or thermoplastic Determination of hardness (hardness between 10 IRHD and 100 IRHD) WARNING Persons using this International Standard should be familiar with normal laboratory practice. This standa
17、rd does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions. CAUTION Certain procedures specified in this Interna
18、tional Standard may involve the use or generation of substances, or the generation of waste, that could constitute a local environmental hazard. Reference should be made to appropriate documentation on safe handling and disposal after use. 1 Scope This International Standard specifies four methods f
19、or the determination of the hardness of vulcanized or thermoplastic rubbers on flat surfaces (standard-hardness methods) and four methods for the determination of the apparent hardness of curved surfaces (apparent-hardness methods). The hardness is expressed in international rubber hardness degrees
20、(IRHD). The methods cover the hardness range from 10 IRHD to 100 IRHD. These methods differ primarily in the diameter of the indenting ball and the magnitude of the indenting force, these being chosen to suit the particular application. The range of applicability of each method is indicated in Figur
21、e 1. This International Standard does not specify a method for the determination of hardness by a pocket hardness meter, which is described in ISO 7619-2. This International Standard specifies the following four methods for the determination of standard hardness. Method N (normal test) is appropriat
22、e for rubbers with a hardness in the range 35 IRHD to 85 IRHD, but can also be used for hardnesses in the range 30 IRHD to 95 IRHD. Method H (high-hardness test) is appropriate for rubbers with a hardness in the range 85 IRHD to 100 IRHD. Method L (low-hardness test) is appropriate for rubbers with
23、a hardness in the range 10 IRHD to 35 IRHD. Method M (microtest) is essentially a scaled-down version of the normal test method N, permitting the testing of thinner and smaller test pieces. It is appropriate for rubbers with a hardness in the range 35 IRHD to 85 IRHD, but can also be used for hardne
24、sses in the range 30 IRHD to 95 IRHD. NOTE 1 The value of the hardness obtained by method N within the ranges 85 IRHD to 95 IRHD and 30 IRHD to 35 IRHD might not agree precisely with that obtained using method H or method L, respectively. The difference is not normally significant for technical purp
25、oses. NOTE 2 Because of various surface effects in the rubber and the possibility of slight surface roughness (produced, for example, by buffing), the microtest might not always give results agreeing with those obtained by the normal test. DIN ISO 48:2016-096 This International Standard also specifi
26、es four methods, CN, CH, CL and CM, for the determination of the apparent hardness of curved surfaces. These methods are modifications of methods N, H, L and M, respectively, and are used when the rubber surface tested is curved, in which case there are two possibilities: a) the test piece or produc
27、t tested is large enough for the hardness instrument to rest upon it; or b) the test piece or product tested is small enough for both the test piece and the instrument to rest upon a common support. A variant of b) would be where the test piece rests upon the specimen table of the instrument. Appare
28、nt hardness can also be measured on non-standard flat test pieces using methods N, H, L and M. The procedures described cannot provide for all possible shapes and dimensions of test piece, but cover some of the commonest types, such as O-rings. This International Standard does not specify the determ
29、ination of the apparent hardness of rubber-covered rollers, which is specified in ISO 7267 (all parts). Key X hardness (IRHD) aMethod L and method CL. bMethods N and M and methods CN and CM. cMethod H and method CH. Figure 1 Range of applicability 2 Normative references The following referenced docu
30、ments are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 18898, Rubber Calibration and verification of hardness testers ISO 23529,
31、Rubber General procedures for preparing and conditioning test pieces for physical test methods 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. DIN ISO 48:2016-097 3.1 international rubber hardness degree scale IRHD scale hardness scale chosen so
32、that 0 represents the hardness of material having a Youngs modulus of zero and 100 represents the hardness of a material of infinite Youngs modulus NOTE The following characteristics applying over most of the normal range of hardnesses: a) one international rubber hardness degree always represents a
33、pproximately the same proportional difference in Youngs modulus; b) for highly elastic rubbers, the IRHD and Shore A scales are comparable. 3.2 standard hardness hardness obtained using the procedures described in methods N, H, L and M on test pieces of the standard thickness and not less than the m
34、inimum lateral dimensions specified NOTE Standard hardness is reported to the nearest whole number in IRHD. 3.3 apparent hardness hardness obtained using the procedures described in methods N, H, L and M on test pieces of non-standard dimensions, as well as hardness values obtained using methods CN,
35、 CH, CL and CM NOTE 1 Apparent hardness is reported to the nearest whole number in IRHD. NOTE 2 Values obtained by methods CN, CH, CL and CM are always given as apparent hardnesses since tests are commonly made on the complete article where the thickness of the rubber can vary and, in many cases, th
36、e lateral dimensions might not provide the minimum distance between the indentor and the edge necessary to eliminate edge effects. Thus the readings obtained do not in general coincide with readings obtained on standard test pieces as defined in methods N, H, L and M or on a flat parallel-faced slab
37、 of the same thickness as the article. Moreover, the readings might depend appreciably on the method of support of the article and whether or not a presser foot is used. Therefore, results obtained on curved surfaces are arbitrary values applicable only to test pieces or articles of one particular s
38、hape and of particular dimensions, and supported in one particular way, and in extreme cases such values can differ from the standard hardness by as much as 10 IRHD. Furthermore, surfaces that have been buffed or otherwise prepared to remove cloth markings, etc., can give slightly different hardness
39、 values from those with a smooth, moulded finish. 4 Principle The hardness test consists in measuring the difference between the depths of indentation of a ball into the rubber under a small contact force and a large (indenting) force. From this difference, multiplied when using the microtest by the
40、 scale factor 6, the hardness in IRHD is obtained from Tables 3 to 5 or from graphs based on these tables or from a scale, reading directly in IRHD, calculated from the tables and fitted to the indentation-measuring instrument. These tables and curves are derived from the empirical relationship betw
41、een indentation depth and hardness given in Annex A. 5 Apparatus 5.1 General Calibration and verification of the apparatus shall be performed in accordance with ISO 18898. 5.2 Methods N, H, L and M The essential parts of the apparatus are as specified in 5.2.1 to 5.2.6, the appropriate dimensions an
42、d forces being shown in Table 1. DIN ISO 48:2016-098 5.2.1 Vertical plunger, having a rigid ball or spherical surface on the lower end, and means for supporting the plunger so that the spherical tip is kept slightly above the surface of the annular foot prior to applying the contact force. 5.2.2 Mea
43、ns for applying a contact force and an additional indenting force to the plunger, making allowance for the mass of the plunger, including any fittings attached to it, and for the force of any spring acting on it, so that the forces actually transmitted through the spherical end of the plunger are as
44、 specified. 5.2.3 Means for measuring the increase in depth of indentation of the plunger caused by the indenting force, either in metric units or reading directly in IRHD. The gauge employed may be mechanical, optical or electrical. 5.2.4 Flat annular foot, normal to the axis of the plunger and hav
45、ing a central hole for the passage of the plunger. The foot rests upon the test piece and exerts a pressure on it of 30 kPa 5 kPa provided that the total load on the foot does not fall outside the values given in Table 1. The foot shall be rigidly connected to the indentation-measuring device, so th
46、at a measurement is made of the movement of the plunger relative to the foot (i.e. the top surface of the test piece), not relative to the surface supporting the test piece. Table 1 Forces and dimensions of apparatus Force on ball Diameters Contact Indenting Total Force on foot Test mm N N N N Metho
47、d N (normal test) Ball 2,50 0,01 Foot 20 1 Hole 6 1 0,30 0,02 5,40 0,01 5,70 0,03 8,3 1,5 Method H (high hardness) Ball 1,00 0,01 Foot 20 1 Hole 6 1 0,30 0,02 5,40 0,01 5,70 0,03 8,3 1,5 Method L (Iow hardness) Ball 5,00 0,01 Foot 22 1 Hole 10 1 0,30 0,02 5,40 0,01 5,70 0,03 8,3 1,5 Diameters mm Contact mN Indenting mN Total mN Force on foot mN Method M (microtest) Ball 0,395 0,005 Foot 3,35 0,15 Hole 1,00 0,15 8,3 0,5 145 0,5 153,3 1,0 235 30 NOTE 1 In the microtest, when using instruments in which the test piece table is p
