BS EN ISO 7231:2023

• — method A, for conventional types of flexible cellular polymeric material;
• — method B, for all types of flexible cellular polymeric material, but especially for materials with a low permeability to air.

• — method B1: with manual measurement;
• — method B2: with automatic measurement.

NOTE 1 Air flow values can be used to give an indication of the effects of formulation and production variables on the cellular structure.

NOTE 2 In this document, the expression “conventional type of flexible cellular polymeric material” means types which are unsuitable for sealing purposes.