差動トランスを用いた紙厚測定法について

抄録

Accurate determination of paper thickness and measurement of the variation profile of the thickness are among the detailed items of information on sheet geometry essential to the understanding of paper quality. Local density variation may also govern the load-elongation, behavior and printability of the sheet. To describe such kinds of sheet geometry requires measuring the thickness of a given spot in a sheet.
A thickness measurement device which uses a linear variable differential transducer (LVDT) has been assembled and tested. The LVDT was scanned by a spiral grooved rod connected to a stepping motor whose rotation speed could be controlled by a pulse generator.
The first step in this trial involved comparing the validity of the mean thickness obtained by this method with that determined by the mercury displacement method. Thicknesses determined by the two methods on more than 40 specimens tested were found to be very similar.
This device has the potential to obtain a thickness variation profile which will enable us to carry out frequency analysis of the profile and to obtain local sheet density variation. Details will be reported elsewhere.