Patent ID: 8077312

Claim:
A device for calibrating a spectrophotometric system having a sensor portion with a light source and at least one light detector, comprising: an enclosure that includes: at least two windows formed in the enclosure, the two windows having a predetermined spacing from one another; each inside surface of the enclosure being of a color that absorbs a predetermined amount of light entering the enclosure through a first one of the windows and emanating from the light source; and a diffuse reflectance member disposed inside the enclosure in a predetermined location therewithin to reflect a predetermined amount of the light entering the enclosure from the light source through the first one of the windows to the second one of the windows to the at least one light detector, an amount of the light reflected by the member to the second window being attenuated in magnitude as compared to an amount of light entering the enclosure through the first window, the diffuse reflectance member being of a color that reflects light.