Figure 20. Hoistway and Elevator Entrances. Hall call buttons shall be mounted 42 inches (1065 mm) measured from the floor to the centerline between the buttons. Hall lanterns shall be mounted 72 inches (1830 mm) minimum measured from the floor to the centerline beteen the up and down indicators. Raised and Braille characters on hoistway entrances shall be mounted with the centerline at 60 inches (1525 mm) above the floor. Sensors for the required door protective and reopening device shall detect an obstruction passing through the door opening at heights of 5 inches (125 mm), indicated by a dashed line A and 29 inches (735 mm), indicated by a dashed line B. Each is measured from the floor. A note indicates, "The automatic door reopening device is activated if an object passes through either line A or line B. Line A and line B represent the vertical locations of the door reopening device not requiring contact."