Abstract: A method, system and apparatus for improving at least one of a) optical interactance measurements, b) optical transmittance measurements and c) optical reflectance measurements. The apparatus has a probe having a body portion and an tip portion. The body portion has a central tubular element having an opening therethrough. The tip portion has a central aperture and a number that is a plurality of ring openings therein. At least some of the plurality of rings are angled with respect to a longitudinal axis of the probe. A plurality of fiber optic bundles corresponds in number at least to the number of ring openings, and at least one fiber optic bundle is arranged at one end of the longitudinal axis for receiving specimen information and at another end of the longitudinal axis connected to a detector for receiving a signal.

Abstract: A fluid sample cell comprising a sample compartment of precisely predetermined depth bounded by opposed surfaces of a transparent window and a diffuse mirror is disclosed, and comprises inlet and outlet ports for the flow of a series of successive samples into and through said sample compartment and the spectroscopic analysis thereof by irradiation and detection of transmitted and reflected radiation.