METHOD FOR COMPLEX ASSESSMENT OF SHAPE AND SIZE OF EDGE-SURFACED LUMBER Russian patent published in 2009 - IPC G01B5/28 

FIELD: physics, measurement.

SUBSTANCE: invention is related to woodworking industry and may be used for complex assessment of inherent errors in measurements (IME) of width and longitudinal warpage (LW) of edge-surfaced boards, especially boards with length of up to 6 and more metres. Assessment of IME in width and LW of boards is carried out on the basis of making closed size circuit for each control section (ECS) of two neighboring boards sawed from single beam, laid onto flat support with gap between them, symmetrically to longitudinal axis passing through middles of gaskets that create clearance, and fixed in this position for prevention of boards shift in process of measurements. In ECS width of boards (B_1i and B_2i) is measured, distance between their edges, and closed size circuit is made Y_2i=B_1i+B_2i+Y_1i, mm. Total error of all 4 measurements in each control section Δi is detected by difference between rated B_ir and measured B_im width of coupled boards: Δi =B_ir-B_im, mm, besides rated width of both boards is detected by difference of distances between edges, and measured width - by sum of measured widths. Assessment of lumber shape is carried out by values of edge sagging, defined as semi-difference of distances from appropriate edges to their rectilinear base, passing through extreme points of edges at board ends.

EFFECT: provision of complex assessment of widths and longitudinal warpage of boards on both edges in each specific section; possibility to check correctness of measurements (detection of gross errors) in each specific section; possibility of total assessment of measurement errors; possibility of statistical assessment of average errors of measurements in all control sections.

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