Historical
T 551 om-06
Thickness of paper and paperboard (soft platen method)
This method describes a procedure for measuring the thickness of a single sheet of paper or paperboard using soft synthetic rubber platens against the paper to minimize the effect of surface roughness. This method is not to be confused with nor substituted for TAPPI T 411 “Thickness (Caliper) of Paper and Paperboard and Combined Board.” It is to be used primarily for sheet density calculations. Because of the relatively high pressure (50 kPa), this method may not be suitable for measurement of tissue or other soft or low density materials, because the structure may collapse at the prescribed pressure of 50 kPa (7.2 psi).
Technical Association of the Pulp and Paper Industry [tappi]