UNI 7319-1974 Elastomers: tests of vulcanized rubbers. Determination of international rubber hardness on test pieces of nonstandard thickness and on finished articles.
This standard concerns measurements carried out with the normal durometer on finished products or portions of them having a thickness of between 4 and 50 mm at the measurement point. It also has as its object the measurements carried out with the microdurometer on finished products or portions of them having a thickness of between 1 and 4 mm at the measurement point. 2 The measurement of hardness carried out with a normal durometer on finished products or portions of them is permitted in cases where they have smooth, flat and sufficiently large surfaces, so that the measurement can be carried out at least at the distances from the edge or from any discontinuities, foreseen in the table I. For measurement with the microhardness tester, the distance from the edge or from any discontinuities (see table I) must be no less than the thickness and in no case less than 2 mm. 3 With the above limitations, the measurement is also permitted on finished products or portions of them that have smooth and curved surfaces with a radius of curvature of no less than 10 mm. Finished articles with a radius of curvature < 10 mm (for example ring gaskets) can be subject to hardness measurement using a microdurometer. However, the results obtained are not comparable with those obtained on flat objects. Table I — Minimum distances from the edge Thickness of rubber Minimum distance from the edge or from any discontinuities mm mm For measurements with a normal durometer 4 7 6 8 8 9 10 10 15 11.5 25 13 50 25 For measurements with a microdurometer up to 2 2 3 3 4 4
UNI 7319-1974 history
1974UNI 7319-1974 Elastomers: tests of vulcanized rubbers. Determination of international rubber hardness on test pieces of nonstandard thickness and on finished articles.