Table 2.
Results of tree-ring analysis according to the feed speed of resistograph

Species Number of tree ring Avg. of latewood width (%) Feed speed (cm/min) Needle speed (r/min)
Larch (Larix kaempferi) 36 27.92 100 1500
Douglas fir (Pseudotsuga menziesii) 29 31.71 100 1500
Korean pine (Pinus koraiensis) 36 12.94 175 1500
Fir (Abies holophylla) 32 14.53 150 1500
Zelkova (Zelkova serrata) 63 75.97 75 1500