Abstract: A calibration device is provided for in vitro calibration of a light guide. The calibration device has a surface defining a cavity having an open end and a closed end opposite the open end. The opening is sized to receive the end portion of a light guide and a stop is provided near the closed end to prevent the light guide from contacting the inner surface of the closed end and to define an air gap between the end face of the light guide and the inner surface of the closed end. The inner surface of the closed end is flat and perpendicular to the longitudinal axis of the light guide. The light guide directs light from the end face of the light guide across the gap and against the flat surface. The calibration device is formed of a suitable material, such as polyethylene, with a plurality of light scattering particles and a plurality of light absorbing particles having neutral density filter properties uniformly distributed therein.

Abstract: A biological fiber optic probe chemical indicator device is disclosed. Structurally, the probe comprises at least one strand of optical fiber terminating in a coupling arrangement with a disposable sleeve assembly including a chemical indicator system for physiological substances. The disposable sleeve sensor element comprises a tubular housing with annular wall portions defining a female coupling channel means and a casing for a chemical reagent indicator.