All the models of this instrument are similar. In one model the sheet to be tested is made to pass through two flat parallel plates. The top plate has straight through cylindrical holes to accommodate inverted cup shaped sample chambers and about two inch diameter samples. The bottom plate also has through holes aligned with the holes in the top plate. There are five chambers over the product width of about twenty inches. The chamber has gaskets at its bottom rim to make a pressure tight seal with the sheet when the chamber goes down the hole in the top plate to make contact with the sheet. The top of the chamber is connected to the pressure transducer to measure pressure just above the sample. The sample chamber is also connected to a gas line to supply pressurized gas to the chamber. The outlet of a small valve for discharging a specified amount of wetting liquid on the sample in the sample chamber is allowed to pass in to the chamber. The valve is computer controlled to discharge the wetting liquid at the desired time.