Interferometric measurement signals are detected by a single optical interferometric interrogator for a length of a sensing light guide and an interferometric measurement data set corresponding to the interferometric measurement signals is generated. The interferometric measurement data set is transformed into a spectral domain to produce a transformed interferometric measurement data set. The transformed interferometric measurement data set is compared to a baseline interferometric data set to identify a time-varying signal corresponding to a time-varying disturbance. The baseline interferometric data set is representative of the sensing light guide not being subjected to the time-varying disturbance. A compensating signal is determined from the time-varying signal and used to compensate at least a portion of the interferometric measurement data set for the time-varying disturbance as part of producing a measurement of the parameter.

An optical interrogation system, e.g., an OFDR-based system, measures local changes of index of refraction of a sensing light guide subjected to a time-varying disturbance. Interferometric measurement signals detected for a length of the sensing light guide are transformed into the spectral domain. A time varying signal is determined from the transformed interferometric measurement data set. A compensating signal is determined from the time varying signal which is used to compensate the interferometric measurement data set for the time-varying disturbance. The compensation technique may be applied along the length of the light guide.

An optical interrogation system, e.g., an OFDR-based system, measures local changes of index of refraction of a sensing light guide subjected to a time-varying disturbance. Interferometric measurement signals detected for a length of the sensing light guide are transformed into the spectral domain. A time varying signal is determined from the transformed interferometric measurement data set. A compensating signal is determined from the time varying signal which is used to compensate the interferometric measurement data set for the time-varying disturbance. The compensation technique may be applied along the length of the light guide.

The attenuation and other optical properties of a medium are exploited to measure a thickness of the medium between a sensor and a target surface. Disclosed herein are various mediums, arrangements of hardware, and processing techniques that can be used to capture these thickness measurements and obtain three-dimensional images of the target surface in a variety of imaging contexts. This includes general techniques for imaging interior/concave surfaces as well as exterior/convex surfaces, as well as specific adaptations of these techniques to imaging ear canals, human dentition, and so forth.

The present disclosure provides a system and method for providing an improved protective coating for a substrate that may be inspected using the unaided eye or other apparatus under available light. The protective coating is mixed with an additive including flakes or particles that, when applied to the substrate as part of the protective coating, allow the user to empirically determine if the surface has received an adequate protective coat. The determination of whether or not any defects exist may include comparing the observed appearance of the specialty pigment particles with a comparative standard.

The attenuation and other optical properties of a medium are exploited to measure a thickness of the medium between a sensor and a target surface. Disclosed herein are various mediums, arrangements of hardware, and processing techniques that can be used to capture these thickness measurements and obtain three-dimensional images of the target surface in a variety of imaging contexts. This includes general techniques for imaging interior/concave surfaces as well as exterior/convex surfaces, as well as specific adaptations of these techniques to imaging ear canals, human dentition, and so forth.

The invention is directed to a detectable and stable composition comprising an organofunctional silane and/or hydrolyzate and/or partial or complete condensate thereof, a colloidal metal oxide, a water soluble organic dye having a positive charge and a counterion derived from a carboxylic acid of from 1 to 6 carbon atoms, and water. The invention is also directed to a method for determining the uniformity and film thickness of a detectable composition applied to a substrate comprising applying to the surface of the substrate the detectable composition and measuring an optical property of the applied coating, the resulting measurement being related to the uniformity of the applied composition.

The present disclosure provides a system and method for providing an improved protective coating for a substrate that may be inspected using the unaided eye or other apparatus under available light. The protective coating is mixed with an additive comprising flakes or particles that, when applied to the substrate as part of the protective coating, allow the user to empirically determine if the surface has received an adequate protective coat. The determination of whether or not any defects exist may include comparing the observed appearance of the specialty pigment particles with a comparative standard.

Disclosed herein is a protective film detecting method of detecting the formed condition of a protective film formed on the front side of a workpiece. The protective film detecting method includes a fluorescence intensity measuring step of forming a plurality of reference protective films having different thicknesses on the front sides of a plurality of reference workpieces, next applying excitation light absorbable by an absorbing agent contained in each reference protective film to each reference protective film, and next measuring the intensity of fluorescence emitted from the absorbing agent due to the absorption of the excitation light, and a threshold deciding step of deciding a threshold of the fluorescence intensity corresponding to a desired one of the different thicknesses of the reference protective films according to the fluorescence intensity measured above.

Disclosed herein is a protective film detecting method of detecting the formed condition of a protective film formed on the front side of a workpiece. The protective film detecting method includes a fluorescence intensity measuring step of forming a plurality of reference protective films having different thicknesses on the front sides of a plurality of reference workpieces, next applying excitation light absorbable by an absorbing agent contained in each reference protective film to each reference protective film, and next measuring the intensity of fluorescence emitted from the absorbing agent due to the absorption of the excitation light, and a threshold deciding step of deciding a threshold of the fluorescence intensity corresponding to a desired one of the different thicknesses of the reference protective films according to the fluorescence intensity measured above.