本文件规定了四种测定平面硫化橡胶或热塑性橡胶硬度的方法（标准硬度法）和四种测定曲面表观硬度的方法（表观硬度法）。硬度以国际橡胶硬度（IRHD）表示。这些方法的硬度范围从10 IRHD到100 IRHD。 这些方法的主要区别在于压痕球的直径和压痕力的大小，选择这些方法是为了适合特定的应用。每种方法的适用范围如图1所示。 本文件未规定使用袖珍硬度计测定硬度的方法，如ISO 48-5所述。 本文件规定了以下四种测定标准硬度的方法。 -方法N（正常试验）适用于硬度在35 IRHD至85 IRHD范围内的橡胶，但也可用于硬度在30 IRHD至95 IRHD范围内的橡胶。 -方法H（高硬度试验）适用于硬度在85 IRHD至100 IRHD范围内的橡胶。 -方法L（低硬度试验）适用于硬度在10 IRHD至35 IRHD范围内的橡胶。 -方法M（显微试验）本质上是普通试验方法N的缩小版，允许对更薄和更小的试样进行试验。它适用于硬度在35 IRHD至85 IRHD范围内的橡胶，但也可用于硬度在30 IRHD至95 IRHD范围内的橡胶。 注1:在85 IRHD至95 IRHD和30 IRHD至35 IRHD范围内，通过方法N获得的硬度值可能与分别使用方法H或方法L获得的硬度值不完全一致。 就技术目的而言，这种差异通常并不显著。 注2:由于橡胶中存在各种表面效应，并且可能存在轻微的表面粗糙度（例如，通过抛光产生），因此微观试验的结果可能并不总是与常规试验的结果一致。 本文件还规定了四种测定曲面表观硬度的方法:CN、CH、CL和CM。这些方法分别是对方法N、H、L和M的修改，并在试验橡胶表面弯曲时使用，在这种情况下有两种可能性: a） 被测试件或产品足够大，硬度计可以放在其上； b） 测试的试件或产品足够小，使试件和仪器都能放在一个共同的支架上。 b）的一种变体是，试样位于仪器的支撑面上。 也可以使用方法N、H、L和M在非标准扁平试样上测量表观硬度。 所述程序不能提供试件的所有可能形状和尺寸，但涵盖了一些最常见的类型，如O形圈。

This document 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. 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 Figure 1. This document does not specify a method for the determination of hardness by a pocket hardness meter, which is described in ISO 48-5. This document specifies the following four methods for the determination of standard hardness. — Method N (normal test) is appropriate 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 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 hardnesses 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 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 might not always give results agreeing with those obtained by the normal test. This document also specifies 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 product tested is large enough for the hardness instrument to rest upon it; 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 support surface of the instrument. Apparent 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.