1AS1683.15.2—1990 Australian Standard®
M e t h o d s o f t e s t f o r e l a s t o m e r s
M e t h o d15.2:D u r o m e t e r h a r d n e s s
PREFACE
This Standard was prepared by the Standards Australia Committee on Analysis and Testing
of Elastomers under the direction of Committee RU/—,Standards for the Rubber Industry
to superde,in part,AS1683.15—1976,Methods of Test for Rubber Part15:Indentation
Hardness of Rubber and Plastics by Means of a Durometer.
This edition corrects some errors in equations and introduces standard rubbers as a means
of verifying durometers.At the same time,the opportunity has been taken to introduce the
dead load hardness procedure which is specified in Method15.1.
In the preparation of this Standard,account was taken of the following:坟墓对联
ISO
48—1979Vulcanized rubbers—Determination of hardness(hardness between
30and85IRHD)
BS
903—1969Methods of testing vulcanized rubber
Part A26:Determination of hardness
2719—1975Methods of u and calibration of pocket type rubber hardness meters
ASTM
D2240—1986Test method for rubber property—Durometer hardness
FOREWORD
Hardness is determined by the penetration of specified indentors into the material under prescribed conditions.The method permits measurement of initial indentation or the indentation after specified periods,or both.The indentation hardness is inverly related to
the penetration of the indentor and is dependent on the elastic modulus and visco-elastic
behaviour of the material.The shape of the indentor and the force applied to it influence the
results obtained and thus there may be no simple relationship between the results obtained
using the different types of hardness-measuring instruments.
Hardness of elastomeric materials is measured on three scales,as follows:
(a)International Rubber Hardness Degrees(IRHD),as ud in the dead load method
(AS1683.15.1).
(b)Durometer Hardness Degrees,Type A,ud for measuring softer materials
(AS1683.15.2).
NOTE:Such materials would have a value approximating30-90IRHD.
(c)Durometer Hardness Degrees,Type D,ud for measuring harder materials
(AS1683.15.2).
NOTE:Such materials would have a value above90IRHD.
No simple relationship exists between indentation hardness determined by AS1683.15.2and
any fundamental property of the materials tested.
METHOD
1SCOPE This method ts out the procedure for determining durometer hardness of elastomeric materials.
Procedures are also given for verification of testing equipment.
AS1683.15.2—19902
This method us two types of durometers,Type A and Type D.The Type A durometer is
ud for measuring elastomeric materials in the normal hardness range(30-90IRHD)and
Type D for elastomeric materials in the high hardness range(above90IRHD).
2PRINCIPLE Hardness is determined by the penetration of specified indentors into the
material under prescribed conditions.
3REFERENCED DOCUMENTS The following documents are referred to in this
Standard:
岳阳楼记作者AS
1683Methods of test for rubber
1683.15.1Method15.1:International rubber hardness(IRHD).
ISO
48Vulcanized rubbers—Determination of hardness(hardness between30and
85IRHD).
ASTM
D2240Test method for rubber property—Durometer hardness
BS
903Methods of testing vulcanized rubber
Part A26:Determination of hardness
4APPARATUS A durometer is required,which shall consist of the following
components:
(a)A Pressor foot—having a hole between2.5mm and3.2mm in diameter,centred at
least6mm from any edge of the foot.
淘宝网简介
(b)Indentor—formed from hardened steel rod,of between1.15mm and1.40mm in
diameter,to the shape and dimensions shown in Figure1for Type A durometers or in
Figure2for Type D durometers.
(c)Indicating device—on which the amount of extension of the point of the indentor may
be read in graduations ranging from0degrees hardness for full extension of2.46mm
to2.54mm,to100degrees hardness for zero extension.Zero extension is obtained by
placing the pressor foot and indentor in firm contact with a flat piece of glass.
NOTE:Type A‘Shore’Durometers rial numbers1to16300and16351to16900and type A-2‘Shore’
Durometers numbers1to8077do not meet the requirements of2.46mm to2.54mm extension of the indentor六堡茶功效
at0degrees hardness reading.The durometers will give readings which are low by amounts ranging from
3degrees at30degrees hardness to1degree at90degrees hardness.
(d)A calibrated spring—for applying force to the indentor in accordance with one of the
following equations:
(i)F=0.550+0.075H A4(1)
where
F is the force,in newtowns,and
is the hardness reading on a Type A durometer.
H
A
4(2) (ii)F=0.445H
D
where
F is the force,in newtowns,and
is the hardness reading on a Type D durometer.
H
地球仪英文D
5CALIBRATION OF DUROMETERS BY MECHANICAL MEANS The spring
shall be calibrated by mechanical means.This is achieved by supporting the durometer in
a vertical position and by resting the point of the indentor on a small spacer at the centre
of one pan of a balance,as shown in Figure3,in order to prevent interference between我的小王子
pressor foot and pan.The spacer shall have a small cylindrical stem approximately2.5mm
in height and1.25mm in diameter,and shall be slightly cupped on top to accommodate the
indentor point.The mass of the spacer may be balanced by a tare on the opposite pan of the
balance.Known mass may be added to the opposite pan to balance the force on the
indentor at various scale readings.The measured force shall equal the force calculated by
either Equation4(1)to within±0.08N,or Equation4(2)to within±0.44N.(See
Clau4(d).)
3AS1683.15.2—1990
DIMENSIONS IN MILLIMETRES
FIGURE1INDENTOR FOR TYPE A DUROMETER
DIMENSIONS IN MILLIMETRES
FIGURE2INDENTOR FOR TYPE D DUROMETER
FIGURE3APPARATUS FOR CALIBRATION OF DUROMETER SPRING
AS1683.15.2—19904
6TEST SPECIMEN The test specimen shall be at least6mm in thickness unless it can
be shown that identical results can be obtained with a thinner specimen.
NOTE:A specimen may be compod of plied thinner pieces to obtain the necessary thickness,but
determinations made on such specimens might not agree with tho made on one-piece specimens becau the
surfaces between plies might not be in complete contact.
The lateral dimensions of the specimen shall be sufficient to permit measurements at least
12mm from any edge unless it is known that identical results are obtainable when回味鸭血粉丝
measurements are made at a shorter distance from an edge.The surface of the specimen
shall be sufficiently flat to permit the pressor foot to contact the specimen over an area
having a radius of at least6mm from the indentor point.
NOTE:A reliable hardness determination cannot be made on a rounded,uneven,or rough surface.
7CONDITIONING Tests shall be carried out at23±2°C if the temperature of test is立方厘米和立方米
not specified in the referring Standard.For elastomers who hardness is not affected by
relative humidity,the durometer and specimens shall be conditioned at the temperature of
test for at least16h before testing.For elastomers who hardness is affected by the relative
humidity,the specimens shall be conditioned at the temperature of the test at50±5percent
relative humidity for at least16h before testing,unless otherwi specified in the referring
Standard.
NOTES:
1.When transferring the durometer from a chamber below room temperature to an environment at a higher
temperature,it is advisable that the durometer be immediately placed in a suitable desiccator or airtight
container until its temperature stabilizes,to prevent any condensation on or in the durometer.
2.If tests are ud for production control purpos,shorter conditioning times may be acceptable provided that
allowance is made for environmental effects.
8PROCEDURE The procedure shall be as follows:
(a)Place the specimen on a horizontal hard surface.Hold the durometer in a vertical
position with the point of the indentor at least12mm from any edge of the specimen,
unless it is known that identical results are obtainable when measurements are made
with the indentor at a less distance.Apply the pressor foot to the specimen as rapidly
as possible without shock,keeping the foot parallel to the surface of the specimen.
Apply just enough pressure to obtain firm contact between pressor foot and specimen.
NOTE:Better reproducibility may be obtained by using either a durometer stand or a weight centred on the
axis of the indentor,or both,to apply the pressor foot to the specimen.Recommended mass for the weight
are1kg for a Type A durometer and5kg for a Type D durometer.
(b)Unless otherwi specified in the referring Standard,read the scale within1s of
placing the pressor foot in firm contact with the specimen,unless the durometer has
a maximum indicator,in which ca take the maximum reading.
Where a reading after an interval is specified in the referring Standard,hold the pressor
foot in contact with the specimen without change in position or pressure and read the
scale after the specified period.
(c)Make and record measurements of hardness at five different positions on the specimen,
spaced about6mm apart.
NOTE:It is recommended that measurements be made with the Type D durometer when values above90
are obtained with the Type A durometer,and that measurements be made with the Type A durometer when
values less than30are obtained with the Type D durometer.
9VERIFICATION OF TYPE A DUROMETERS Type A durometers may be verified
by using a t of standard reference rubbers covering the range approximately30IRHD to
90IRHD determined as specified in AS1683.15.1.At least6,and preferably up to
12rubber test pieces kept lightly dusted with talc in a suitable covered wooden container
away from light,heat,oil and grea shall be ud.
The rubber test pieces shall be flat discs or squares of at least50mm in lateral dimensions
and of uniform thickness8mm to10mm.If in a container consisting of a flat ca
provided with a piece of plate glass on which the rubber test pieces rest,the test pieces need
not be taken out and handled except during checks using the dead-load method described
in AS1683.15.1.This should be done at intervals of not more than six months.
NOTES:
1A t of standard rubbers,if stored as above,should remain rviceable for veral years.
2It is recommended that well vulcanized natural rubber compounds be ud for obtaining the t of standard reference rubbers,for which the durometer A scale is a clo approximation in the30-90IRHD range.
3It is advisable that standard reference rubbers be replaced when either they exhibit a significant change in hardness or they show excessive surface deterioration.
4It is recommended that standard reference rubbers be calibrated against a certified dead-load IRHD hardness tester at intervals not exceeding2years.
5It is advisable that durometers in regular u be verified at least monthly.
5AS1683.15.2—1990
10REPORT.The report shall include the following:
(a)Sample identification.
(b)Description of test specimen,including thickness and number of plies and shape.
(c)Type of hardness tester.
(d)Temperature of test,and humidity if relevant.
(e)Interval after which reading was taken(if appropriate).(See Clau8(b).)
(f)Date of test.
(g)The median hardness,expresd in Type A or Type D degrees.
(h)The number of this Australian AS1683.15.2.
(PAGES6AND7IN THE HARD COPY ARE BLANK)
