公开(公告)号：EP1208375A1

公开(公告)日：2002-05-29

申请号：EP00950113.1

申请日：2000-07-27

申请人： Carter Holt Harvey Limited

发明人： HARRIS, Paul, David ,  ANDREWS, Michael, Kenneth

IPC分类号： G01N33/46 ,  G01N29/18

CPC分类号： G01N3/48 ,  G01N29/045 ,  G01N29/46 ,  G01N33/46 ,  G01N33/48 ,  G01N2203/0623 ,  G01N2291/015 ,  G01N2291/0238 ,  G01N2291/02827 ,  G01N2291/0421

摘要： Apparatus (preferably portable) enabling a felled tree stem or log (2), tapped at one end in order to generate an acoustic wave, to have its stiffness characterised echo data both sensed and analysed. The analysis is with best fit recognition procedure and/or one that emphasises high harmonics to determine fundamental frequency related to acoustic speed which is indicative of the stiffness characteristics of the tree stem or log. The apparatus uses an accelerometer pressed compliantly against an end of the tree stem or log to detect reflections from the other end after impacting the first end. The accelerometer is compliantly mounted in a sensing head (1) connected by a flexible link to a housing carrying processing and display means (4, 5, 6). Also disclosed is a method of cutting a stem (2) into logs of predicted speeds by establishing a function which represents the nature of speed variation with distance along the stem characteristic for a species and locality. The average speed along a stem and the speed function are used to compute the likely speed at points along the stem, then marking and routing logs cut from the stem according to their speed.

公开(公告)号：EP1159610A1

公开(公告)日：2001-12-05

申请号：EP99940745.5

申请日：1999-08-17

申请人： Carter Holt Harvey Limited

发明人： ANDREWS, Michael, Kenneth ,  HARRIS, Paul, David ,  CARTER, Peter, Charles, Stratton ,  RAWLEY, Brian, Andrew ,  LAUSBERG, Marcus, Jean, François

IPC分类号： G01N33/46 ,  G01N29/18 ,  G01N3/34

CPC分类号： G01N3/34 ,  G01N33/46 ,  G01N2203/0623 ,  G01N2291/0238 ,  G01N2291/0421

摘要： The present invention relates to the use of a single end testing of stems of felled trees whereby by inducing a sonic wave with an impact and by reference to detected reflections and with a knowledge of the length of the stem the stiffness and/or strength characteristics of the stem or logs to be cut therefrom can be derived. A preferred procedure is a determination of the fundamental frequency f0 which relates to velocity V, the speed of longitudinal compressional motions along the stem, and L, the length of the stem, as follows: V=2Lf0. From that value V or a function of V can be derived an indicator of stiffness and/or strength. For example the modulus of elasticity (MOE) is such an indicator and can be determined by the equation MOE=ς V2 where ς is density. For green felled timber ς can be estimated as approximating 1000 kg/m3.