Systems and methods for verifying the opacity of an inflatable membrane

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.

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.