| 摘要 |
The sawn board (1) has a constant thickness. A measurement device can be fixed or movable in a plane parallel with the board sides. The board is moved at right angles to its longitudinal direction in a plane through one of its sides with a known, constant speed, or past a position indicator. Light is emitted in a narrow beam from one or more light emitters (2,3) towards at least one of the plain sides of the board. Reflected light is picked up in one or more light-absorbing components. The light strength in the reflected light is measured and compared with that of the emitted light. A signal is given when strong reflection occurs or stops, whereby the time or the board position is measured between these processes and converted to a width measurement. |
