Revised Standard from Last Update.

NATIONAL FOREWORD

This draft Indian Standard (Part 10/Sec 2) (Third Revision) which is identical with ISO 815-2 : 2019 ‘Rubber, vulcanized or thermoplastic - Determination of compression set - Part 2: At low temperatures’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on recommendation(s) of the Methods of Test for Rubber and Rubber Products Sectional Committee and approval of the Petroleum, Coal and Related Products Division Council.

Allowing measurement and recording of the compression set at low temperature is very sensitive to testing conditions, and the values obtained can differ a lot especially for type B test pieces. That is why two measurement methods have been introduced. Method 2 generally gives a higher compression set than method 1, and this difference should be taken into account when preparing material specifications.

Those methods are intended to measure the ability of rubbers of hardness within the range 10 IRHD to 95 IRHD to retain their elastic properties at specified temperatures after prolonged compression at constant strain (normally 25 percent) under one of the alternative sets of conditions described. For rubber of nominal hardness 80 IRHD and above, a lower compression strain is used: 15 percent for a nominal hardness from 80 IRHD to 89 IRHD, and 10 percent for a nominal hardness from 90 IRHD to 95 IRHD.