Systems and methods for verifying the opacity of an inflatable membrane

Abstract

Verifying the opacity of an inflatable membrane includes tests to measure the contribution of a background to the noise in the fluorescence signal as an inflatable membrane is stretched. For example, if the inflatable membrane fluoresces red and green light in response to illumination with visible blue light, the ratio of red to green fluoresced light is measured when the membrane is not stretched and then stretched while the membrane sits over a background that is half black and half red. When the change in the ratio of intensities of the two wavelengths of fluoresced light increases more for measurements taken over one portion of the background than the other, then the inflatable membrane is considered transparent to the wavelengths of fluoresced light, and if it increases a similar amount for measurements taken no matter which portion of the background the membrane covered, then the inflatable membrane is considered opaque.

1 .- 19 . (canceled) 
     
     
         20 . A method of verifying an opacity of an inflatable membrane, comprising:
 illuminating an unstrained inflatable membrane with light of an illumination wavelength against a first background having a first color, said illuminating causing the unstrained inflatable membrane to fluoresce at a first fluoresced wavelength of light and a second fluoresced wavelength of light;   measuring a first ratio of intensities of the first fluoresced wavelength of light and the second fluoresced wavelength of light;   illuminating the unstrained inflatable membrane with light of the illumination wavelength against a second background having a second color, said illuminating causing the unstrained inflatable membrane to fluoresce at the first fluoresced wavelength of light and the second fluoresced wavelength of light, wherein the first fluoresced wavelength of light is a same wavelength as the second color;   measuring a second ratio of intensities of the first fluoresced wavelength of light and the second fluoresced wavelength of light;   applying a strain to the unstrained inflatable membrane to obtain a strained inflatable membrane;   illuminating the strained inflatable membrane with light of the illumination wavelength against the first background, said illuminating causing the strained inflatable membrane to fluoresce at the first fluoresced wavelength of light and the second fluoresced wavelength of light;   measuring a third ratio of intensities of the first fluoresced wavelength of light and the second fluoresced wavelength of light;   illuminating the unstrained inflatable membrane with light of the illumination wavelength against the second background, said illuminating causing the strained inflatable membrane to fluoresce at the first fluoresced wavelength of light and the second fluoresced wavelength of light;   measuring a fourth ratio of intensities of the first fluoresced wavelength of light and the second fluoresced wavelength of light; and   determining an opacity of the inflatable membrane based on a comparison of a difference between the fourth ratio and the second ratio and a difference between the third ratio and the first ratio.   
     
     
         21 . The method of  claim 20 , further comprising, determining that the inflatable membrane is transparent to the illumination wavelength if a difference between the fourth ratio and the second ratio is greater than a difference between the third ratio and the first ratio. 
     
     
         22 . The method of  claim 20 , further comprising, determining that the inflatable membrane is opaque to the illumination wavelength if the difference between the fourth ratio and the second ratio is substantially similar to the difference between the third ratio and the first ratio. 
     
     
         23 . The method of  claim 20 , wherein the illumination wavelength is a range of wavelengths and determining the opacity is with respect to the range of wavelengths. 
     
     
         24 . The method of  claim 20 , wherein the inflatable membrane comprises a matrix material, wherein the matrix material forms 95.9% to 98.8% by weight of the inflatable membrane. 
     
     
         25 . The method of  claim 24 , wherein the matrix material comprises a silicone. 
     
     
         26 . The method of  claim 20 , wherein the inflatable membrane comprises a pigment for opacity, wherein the pigment for opacity forms at least 0.12% by weight of the inflatable membrane, and wherein the pigment for opacity is mixed into a matrix material. 
     
     
         27 . The method of  claim 26 , wherein the pigment for opacity comprises a carbon black. 
     
     
         28 . The method of  claim 27 , wherein the carbon black comprises at least one of: a carbon black, a furnace carbon black, a high-purity carbon black, a total amount of polynuclear aromatic hydrocarbons at a level not exceeding about 0.5 parts per million; or a benzopyrene amount at a level not exceeding about 5.0 parts per billion (ppb). 
     
     
         29 . The method of  claim 26 , wherein the pigment for opacity forms 0.2% to 0.3% by weight of the inflatable membrane. 
     
     
         30 . The method of  claim 20 , wherein the inflatable membrane comprises a fluorescent material, wherein the fluorescent material forms 1.0% to 3.8% by weight of the inflatable membrane. 
     
     
         31 . The method of  claim 30 , wherein the fluorescent material is excitable by light with wavelengths ranging from ultra-violet to blue light. 
     
     
         32 . The method of  claim 30 , wherein the fluorescent material has an emission spectra with a peak at a wavelength of about 549 nanometers. 
     
     
         33 . The method of  claim 30 , wherein the fluorescent material comprises at least one of a fluorescent dye, a fluorescent pigment, and an invisible yellow. 
     
     
         34 . The method of  claim 30 , wherein the fluorescent material fluoresces the first fluoresced wavelength of light and the second fluoresced wavelength of light. 
     
     
         35 . The method of  claim 34 , wherein the first fluoresced wavelength of light comprises red light, and wherein the second fluoresced wavelength of light comprises green light. 
     
     
         36 . The method of  claim 20 , wherein measuring is with a 3D scanning system. 
     
     
         37 . An apparatus, comprising:
 an emitter structured to emit light of an illuminating wavelength or a range of illuminating wavelengths to illuminate an interior surface of an inflatable membrane;   a first background comprising a first color and a second background comprising second color;   a detector structured to receive a first fluoresced light and a second fluoresced light from the inflatable membrane against the first background, and the first fluoresced light and the second fluoresced light from the inflatable membrane against the second background, wherein the first fluoresced light and the second color are a similar wavelength; and   a processor structured to measure a ratio of intensities of the first fluoresced light and the second fluoresced light for the inflatable membrane against the first background and the second background and under a condition of strain of the inflatable membrane or a condition of no strain of the inflatable membrane.   
     
     
         38 . The apparatus of  claim 37 , wherein the processor is further structured to determine that the inflatable membrane is opaque to the illuminating wavelength or the range of illuminating wavelengths if a difference between the ratio of intensities of the first fluoresced light and the second fluoresced light against the first background under strain and no strain conditions is substantially similar to a difference between the ratio of intensities of the first fluoresced light and the second fluoresced light against the second background under strain and no strain conditions. 
     
     
         39 . The apparatus of  claim 37 , wherein the processor is further structured to determine that the inflatable membrane is transparent to the illuminating wavelength or the range of illuminating wavelengths if a difference between the ratio of intensities of the first fluoresced light and the second fluoresced light against the second background under strain and no strain conditions is greater than a difference between the ratio of intensities of the first fluoresced light and the second fluoresced light against the first background under strain and no strain conditions.