Patent ID: 8855450

Claim:
A system for measuring properties of a thin film coated glass, comprising: a light source; a spectrometer; at least one pair of probes comprising a first and a second optical probe, wherein each probe has a bifurcated fiber which includes a first leg and a second leg wherein each leg can either emit or collect light, the first optical probe is located above the glass and the second optical probe is located below the glass directly across from the first optical probe, the first leg and second leg of each first and second optical probe are separated from each other by a distance n; a first optical fiber switch is adapted to couple the spectrometer to the first leg of each optical probe; a second optical fiber switch is adapted to couple the light source to the second leg of each optical probe, wherein a film side reflection calibration is performed by coupling the second leg of the optical probe located below the glass to the light source and coupling the first leg of the optical probe located above the glass to the spectrometer and wherein a glass side reflection calibration is performed by coupling the light source to the second leg of the optical probe located above the glass and coupling the spectrometer to the first leg of the optical probe located below the glass thereby eliminating the need for a reference material to be located in front of the probe coupled to the light source.