scope:

This standard specifies two methods of measuring the thicknes of paper and board and of calculating the apparent bulk density or the apparent sheet density from the thickness determinations. The methods are a) measurement of single sheets of paper or board (single sheet thickness); b) measurement of a pack of sheets of paper of grammage up to 224 g/m² (bulking thickness). These methods are not applicable to corrugated fibreboard and, in the case of method b), not to certain soft papers such as tissues which are creped and/or embossed, due to slow or excessive compression which takes place when measurements are made on such materials. It should be noted that two alternative pressures are permitted; the pressure of 100 kPa ± 10 kPa is preferred.