Check scaling involves scaling the logs of certain full length trees 

 after felling and bucking and dividing the scaled volume by the 

 estimated volume of the same trees to determine a correction factoro 

 The number of trees to be check scaled in order to arrive at a reliable 

 correction factor depends upon the precision of volume determinations 

 for individual trees. The closer the estimated volume of each tree 

 agrees or is correlated with its scaled volume, the fewer check scaled 

 trees are neededo Im.proved height and defect estimates and a high 

 degree of accuracy in the application of volume tables are necessary 

 in order to obtain good correlation between the measured and check 

 scale volume. 



When check scaling is planned, that is, when the sampling process 

 is designed to estimate log-scaled volume, the sample size should be 

 determined from Figure 2 in which the correlation coefficient of tree 

 measured and check scaled volumes and the cost ratio of the two 

 processes are considered along with the other variables. The number 

 of trees needed in the check scale under various conditions can then 

 be determined from Figure 3o 



Check scaling presents a problem because of the difficulty of finding 

 full-length trees felled and bucked in the woods under present logging 

 methods. With the use of sampling this difficulty is magnified, because 

 only sample trees can be check scaled. Conspicuously m.arking sample 

 trees aids in locating them for scaling purposes. With improved skill 

 in tree measurement, check scaling can be materially reduced. 



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