| 摘要 |
A method of measuring warp in planar materials (such as boards 4 travelling on a conveyor 2 during manufacture) measures the distance between the planar material 4 and a series of spaced sensors 3 and calculates a composite curvature for the planar material 4. The sensors 3 are provided above the conveyor 2 and measure the height of the boards 4passing below. Warp is calculated using successive trios of sensors (e.g. sensor-1, sensor-2, sensor-3) whereby distance measurements from sensors (e.g. sensor-1, sensor-3) to either side of an intermediate sensor (e.g. sensor-2) are used to calculate the warp height BE (approximately BD) for the section of board being sensed. Inaccuracies of curvature measurement due to stacking and overlapping on a conveyor which occurs in corrugated board production for example) are overcome by taking the position of overlap (board-edge) or gaps between boards into account. |
