Patent ID: 7593107

Claim:
A system for measuring light absorption levels for a liquid for use in a ink jet printing system, the system comprising: a light source operable to provide a light beam; a container adapted to receive a liquid, the container including an opening to provide access to the liquid, the liquid including a light absorption level; a prism disposed over the opening, the prism being operable to direct at least a first portion of the light beam toward the opening to the liquid such that the at least a portion of the first portion of the light beam is reflected back from the liquid forming an attenuated beam; a detector operable to measure at least one of at least a portion of the attenuated beam and a second portion of the light beam, the detector being operable to produce at least one of a liquid measurement signal that is related to the light absorption level of the liquid from the portion of the attenuated beam and a reference signal from the second portion of the light beam; and a device operable to compute a ratio of the liquid measurement signal to the reference signal to determine a signal ratio, wherein the signal ratio is related to the light absorption level of the liquid.