translate English to French: The support should be located at the edge of the trench, at least 1.5 m but not more than 3.5 m from the end wall of the trench where the four upper sensors will be installed.
Le support doit se trouver sur le bord de la tranchÃ©e, entre 1.5 m et 3.5 m de la paroi verticale du bout de la tranchÃ©e oÃ¹ les quatre dÃ©tecteurs supÃ©rieurs seront installÃ©s.