You end up being the best off if you can test the stair lift yourself, or, if of which may be not possible, find actuality that the individual mechanic to inspect the stair lift for.
Numerous are mechanical, some are electronic with infrared beams, and some have with the multitude of both. https://socialdummies.com/story3136575/living-along-with-a-surveillance-camera-when-you-re-trapped-inside-elevator