Methods for determining optical properties with measurements having different average optical depths or thickness sensitivities

A method for determining optical properties of an object, comprising:

• providing light to the object via a probe tip including a plurality of light source/light receiver pairs;
• receiving light from a first light source/light receiver pair, wherein the first light source/light receiver pair is arranged so that a first measurement generates data having a first sensitivity based on a thickness of a material of the object;
• receiving light from a second light source/light receiver pair, wherein the second light source/light receiver pair is arranged so that a second measurement generates data having a second sensitivity based on a thickness of a material of the object, wherein the second sensitivity is different from the first sensitivity;
• processing the data generated from the first and second measurements, wherein optical properties of the object are determined based on the data generated by the first and second measurements.

A system for determining optical properties of an object, the system including a probe tip having one or more light sources and one or more light receivers, wherein the probe tip is positioned in proximity to the object, wherein the probe tip is encompassed by a removable barrier, wherein the barrier has a first, inner surface positioned adjacent the probe tip that has surface characteristics to facilitate insertion of the probe tip into the barrier, wherein the barrier has a second, outer surface that comes into contact with the object and that has surface characteristics to resist sliding of the probe tip with respect to the object when the outer surface is in contact with the object, wherein light from the one or more light sources is returned from the object through the barrier to the one or more light receivers, wherein light received by the one or more light receivers is measured by one or more spectrometer systems, wherein optical properties of the object are determined, wherein the probe tip is coupled to a body, wherein the body encloses the one or more spectrometer systems, wherein optical properties of the object are determined by positioning the probe tip in proximity of the object, wherein a user's hand substantially encompasses at least a portion of the body enclosing the one or more spectrometer systems, wherein the system comprises a handheld spectrophotometer.