ELEVATOR POSITION REFERENCE SYSTEMS AND MONITORING BUILDING SETTLEMENT USING AN ELEVATOR POSITION REFERENCE SYSTEM

An elevator position reference system and a method of monitoring building settlement using such a system are disclosed. The elevator position reference system (3) includes a hoistway (4) extending in a vertical direction. The system also includes a first position measurement tape (8a) extending vertically along a portion of the hoistway (4) and an upper tensioning device (10), connected to an upper end (20a) of the first position measurement tape (8a) so as to apply a tensioning force (30) in the upwards vertical direction. A lower end (22a) of the first position measurement tape (8a) is fixed within the hoistway (4). The system also includes a second position measurement tape (8b) extend vertically along at least some of said portion of the hoistway (4) and a lower tensioning device (12), connected to a lower end (22b) of the second position measurement tape (8b) so as to apply a tensioning force (32) in the downwards vertical direction. An upper end (20b) of the second position measurement tape (8b) is fixed within the hoistway (4).