SAMPLING METHODS IN LOG SCALING

Studies made by B. R. Lexen, Senior Silviculturist at the Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado, U.S.A., on the application of sampling methods in the scaling of lodge-pole and ponderosa pine logs are extended to the scaling of spruce and balsam bolts and small logs in Eastern Canadian pulpwood operations. It was found that Lexen's conclusions held good. Three general methods are available—(1) Random Sampling, (2) Representative or Stratified Random Sampling, and, (3) Mechanical Sampling. These are described and compared as regards accuracy and work entailed.A Random Sampling of two percent provides a reasonably close estimate of the total but refinements in technique and intensification in sampling are necessary if great accuracy is desired. Three refinements in technique are outlined.Mechanical Sampling provides an unbiased estimate of the mean but evaluation of sampling error must be based on Random Samples. Due to ease of application in the field Mechanical Sampling is preferable.