| 摘要 |
Apparatus and method is disclosed for measuring the atmospheric transmission and determining meteorological visual range, these being used in particular on airport runways. A transmitting unit and a receiving unit are each fastened on a vertical tubular structure 1. All the elements responsible for optical alignment measurements are located on a bearing inner tube (5, Fig. 4). A scattered light measuring arrangement 15 is connected to an outer tube (6, Fig.4) and is used to determine a calibration factor. Equipment plates (9, Fig.7), positioned at 90{ to one another in a V-shaped fashion, are arranged in front of the transmitting and receiving unit to protect the components against fouling. The degree of fouling of the equipment plates is determined by a dedicated transmission measuring device and is used to determine a correction factor. An alignment factor is determined from the calibration factor and the correction factor and is used to restore the initial adjustment between receiver and transmitter. |
