ISO 4590:1981

Cellular plastics — Determination of volume percentage of open and closed cells of rigid materials

Specifies a general method ba measurement first of geometrical volume and of the air impenetrable volume of test specimens. This method provides for correcting the apparent open cell volume by taking into account the surface cell opened by cutting during specimen preparation. Two alternative methods and corresponding apparatus are specified for the measurement of the impenetrable volume. The results are to be used for comparison purposes only.