Abstract: An optical measuring device, particularly using spectrophotometry, which comprises at least one group of optical fibers (24) connected to measuring cells, at least one auxiliary optical fiber (30) and at least one selection member connecting the latter to the group. The selective member establishes a link between the auxiliary fiber and one of the fibers of the group. The selection member comprises fixed optical means (32, 34 ) for establishing the link between the group and the auxiliary fiber and retractable seals (36) associated with the fibers of the group and which seal the ends of auxiliary fibers leading to said member.

Abstract: It comprises a support (2), a drum (8) having a winding zone for an optical cable (12) having a plurality of optical fibers, said drum (8) being mounted in rotary manner on a shaft (6) mounted on the fixed support (2), said main optical cable (12) having an end (12b) fixed to the winding zone of said rotary drum, an optical compensating cable (14) spirally wound within drum (8) and having an end fixed to said drum (8) and connected to the end (12b) of the main optical cable (12) and an end mounted on a fixed part (18) of the support.