抄録
A principle and basic characters of the new smoothness tester, equipped with vacuum air-micrometer, was described previously in a report (1). For practical use the studies of this new smoothness tester were carried on and the results are summarized as follows :
(1) For a practical measuring head we developed a multi-ring structure (Fig. 2) the grooves of which are connected to atmosphere and vacuum pump alternately in order to keep six measuring rings in a parallel conjunction. By using this structure the rate of surface air flow is increased, and harmful effects as transverse porosity, unevenness of paper surface and blocking up of the orifice may be lessened (Fig. 7)
(2) Speaking of effects of the ring width and backing materials, reproducibility of the reading is independent of these factors, but transition tendency of the reading is varied by the kind of paper so that paper smoothness ranking is changed by combination of these factors (Tab. 2 and 3. Fig. 5)
(3) Reproducibility of the reading with new tester is enough for practical use . On standardized measuring method any appreciable personal error was not appearing and variability of the reading is mostly introduced by irregularity of paper surface (Tab. 5 and 6)
(4) Comparison tests between two new testers showed no appreciable difference in their smoothness reading (Tab. 7 and 8)
(5) The smoothness values of new tester used rubber -plate backing correlate with Bekk seconds only for measuring non-coated paper, and the Bekk seconds may be led from new tester reading with practically negligible error in shortened measuring time. But this correlation can not be found in coated paper, machine glazed paper and paper board (Fig. 6)
(6) The smoothness value-of new tester used glass-plate backing have a good correlation with printing smoothness of coated paper, non-coated paper, and paper board in a wide range of smoothness value, but a machine glazed paper should be excluded from measuring objects to obtain the more accurate number of printing smoothness ranking, using the new tester (Tab. 10 Fig. 12 and 13)
