| 摘要 |
The apparatus determines the position of the beam path (O) for a pulsed light beam (A) passing through an air-space by measuring the scattered radiation received by a detector device in a measuring station (F) situated on the side of the beam path. The detector device has a sensitivity lobe which has a given limited lobe width (2 DELTA theta ) and which lobe can assume different angles ( alpha ) relative to a reference line (R). In the measuring station (F) the time distance between the front flank and the rear flank of the scattered radiation reaching the detector device, i.e. the pulse width or the pulse length of the scattered radiation, is determined in at least two different angular positions ( alpha ) of the sensitivity lobe. The position of the light beam path is then determined by means of the measured pulse widths in combination with the associated known angular positions of the sensitivity lobe. |
