This part of ISO 9073 specifies a test method for measuring the strike-through time (STT) for each of three subsequent doses of liquid (simulated urine) applied to the surface of a test piece of nonwoven coverstock. The STT is defined as the time taken for a known volume of liquid to pass through the nonwoven that is in contact with an underlying dry standard absorbent pad.

This test method is intended for quality control and is designed for comparison of STT for different nonwoven coverstocks. It does not simulate in-use conditions for finished products.