| 摘要 |
The arrangement comprises an installation platform (500) movable upwards and downwards in the elevator shaft (20), at least one light source (810) arranged at a predetermined position in the elevator shaft (20) below the installation platform (500) and producing a vertically upwards directed collimated light beam (LB1), at least one primary digital imaging device (650) positioned on the installation platform (500) and being arranged to take electronic images of the light beam (LB1) hitting the photosensitive sensor of the at least one primary digital imaging device (650) or of a pattern created by the light beam (LB1) on a reflective or transparent screen positioned at a distance in front of the photosensitive sensor of the at least one primary digital imaging device (650), whereby the horizontal position of the installation platform (500) in relation to the elevator shaft (20) can be measured from the electronic images taken by the at least one primary digital imaging device (650). |
