Porosity and/or permeability measurement device and method

A device for measuring porosity and/or gas permeability of a sheet of material such as paper or cardboard, the device comprising a measurement head comprising a body part having a measurement face configured to be set towards the sheet of material to be measured, the body part comprising, on its measurement face, a first indentation defining a control volume and a sealing arrangement surrounding the first indentation to seal the control volume, and a control flow channel forming a flow connection between the control volume and the outside of the body part for controlling the pressure in the control volume to create a pressure difference across the sheet of material to be measured, characterized in that the sealing arrangement comprises a first aerostatic bearing for forming a contactless sealing between the body part and the sheet of material to be measured.

A method for measuring porosity and/or gas permeability of a sheet of material such as paper, cardboard, or plastic, the method comprising arranging a sealed control volume adjacent to the sheet of material to be measured and controlling the pressure in the control volume to create a pressure difference across the sheet of material to be measured, characterized by using a first aerostatic bearing for forming a contactless sealing between the body part and the sheet of material to be measured.