A fiber optic probe (100) provides in-vitro measurement for measuring fluid media containing bubbles and particulate matter where disturbances to fluid dynamics must be kept to a minimum. The probe transmits light to, and receives light from, the measured fluid media across a light-path gap (119) using two, separate fiber support tubes (107A, 107B) to protect the transmitting and receiving fibers and provide a rigid and resilient structure. Each support tube, containing one or more fibers, is bent ninety degrees in a smooth quarter circle to produce a light path gap that is perpendicular to the longitudinal axis (113) of the probe. A cross-member (125) provides precise alignment of the optical axes or the transmitting and receiving fibers. The small-diameter support tubes reduce hydraulic flow disturbances and debris buildup which would occur with conventional probes during tablet dissolution. The transverse light path gap reduces opportunities for debris buildup and bubble entrapment between transmitting and receiving optical surfaces.
