Abstract: A compact light source for coupling to a movable optic probe may include a light emitting diode (LED), to generate a probe signal at a first bandwidth, an optic coupler, disposed adjacent to the LED, and arranged to couple the probe signal into the movable probe, and a narrow bandpass filter disposed to receive the probe signal at the first bandwidth, and to output the probe signal into the movable probe at a second bandwidth, less than the first bandwidth.

Abstract: An apparatus may include a light emitting diode (LED) assembly, comprising a plurality of LEDs that output radiation at a plurality of different wavelengths, respectively. The LED assembly may be arranged to output a composite probe signal at a plurality of instances, wherein the composite probe signal comprises a plurality of probe signals, generated from the plurality of LEDs, respectively. The apparatus may also include a measurement module that includes an optic probe to direct the composite probe signal through a fluid sample, while moving between a plurality of probe positions at the plurality of instances. The measurement module may include a detector, disposed to detect, at the plurality of instances, a transmitted intensity of the composite probe signal at the plurality of different wavelengths after the composite probe signal passes through the fluid sample.

Abstract: A system may include a light source, to generate a probe signal, comprising incident radiation; an optical probe, to direct the incident radiation through a fluid sample; a motor, to move the optical probe along a probe axis, to change a path length of the incident radiation through the fluid sample; and a detector, to receive the incident radiation as attenuated radiation after passing through the fluid sample. The system may include a control system, arranged to: initiate an absorbance measurement by directing movement of the optical probe along the probe axis; direct the light source to emit the incident radiation; and automatically adjust at least one measurement parameter of a set of measurement parameters for the sample measurement, based upon a slope parameter m, wherein m is derived from a rate of change in an intensity of the attenuated radiation with a change in the path length.

Abstract: A method includes determining whether a variation in probe radiation intensity meets a stability criterion; directing the probe radiation through a probe, when the probe is disposed at a first position, defining a first path length L1 of the probe radiation through the fluid sample; measuring a transmitted intensity I1 of the probe radiation after passing through the fluid sample when the probe is disposed at the first position; directing the probe radiation through the probe when the probe is disposed at a second position, defining a second path length L2 of the probe radiation through the fluid sample; measuring a transmitted intensity I2 of the probe radiation after passing through the fluid sample when the probe is disposed at the second position; and determining a concentration C of a material in the fluid sample based upon L1, I1, L2, and I2, when the stability criterion is met.