DIN ISO 48-2009 硫化或热塑橡胶.硬度的测定(硬度在10 IRHD至100 IRHD之间)(ISO 48:2007),DIN ISO 48:2009-10的英文版本
Rubber, vulcanized or thermoplastic - Determination of hardness (hardness between 10 IRHD and 100 IRHD) (ISO 48:2007);English version of DIN ISO 48:2009-10
1.1 General
This International Standard specifies four methods for 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 (IRHD). The methods cover the hardness range from 10 IRHD to
100 IRHD.
The 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
Figure 1.
The determination of hardness by a pocket hardness meter is described in ISO 7619-2.
1.2 Standard-hardness methods
Method N: Normal test -- This method is appropriate for rubbers with a hardness in the range 35 IRHD to
85 IRHD, but may also be used for hardnesses in the range 30 IRHD to 95 IRHD.
Method H: High-hardness test -- This method is appropriate for rubbers with a hardness in the range 85 IRHD
to 100 IRHD.
Method L: Low-hardness test -- This method is appropriate for rubbers with a hardness in the range 10 IRHD
to 35 IRHD.
Method M: Microtest -- This method 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 may also be used for hardnesses in the range 30 IRHD to 95 IRHD
NOTE 1 The value of the hardness obtained by method N within the ranges from 85 IRHD to 95 IRHD and from
30 IRHD to 35 IRHD may not agree precisely with that obtained using method H or method L, respectively. The difference
is not normally significant for technical purposes.
NOTE 2 Because of various surface effects in the rubber and the possibility of slight surface roughness (produced, for example, by buffing), the microtest may not always give results agreeing with those obtained by the normal test.
1.3 Apparent-hardness methods
Also specified are 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, for cases where
the rubber surface tested is curved. Two cases exist, depending whether
a) the test piece or product tested is large enough for the hardness instrument to rest upon it;
b) it 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 on the specimen table of the instrument
Apparent hardness can also be measured an non-standard flat test pieces usJng 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
Determination of the apparent hardness of rubber-covered rollers is dealt with separately in the various parts
of ISO 7267