Patent ID: 7476842

Claim:
A system for detecting light, the system comprising: a compartment having a body defining an interior wherein the body has an interior surface and a length defined between a first end and a second end of the compartment wherein the interior of the compartment has a pressure; a movable element within the interior of the compartment wherein the movable element has a position within the interior of the compartment; a wall at the first end of the compartment wherein the wall abuts the body of the compartment; a first lens attached to the wall wherein the first lens is located within the interior of the compartment wherein the first lens is spherically shaped and further wherein the first lens encloses the interior and maintains the pressure of the interior; a cavity formed in the wall wherein the first lens is located between the cavity and the interior of the compartment; a light source located within the cavity wherein the light source emits light into the interior of the compartment wherein the interior surface of the compartment absorbs an amount of the light emitted from the light source; and a sensor located within the cavity wherein the sensor detects an intensity of light within the interior of the compartment via the first lens wherein the intensity of the light within the interior of the compartment corresponds to the amount of the light emitted from the light source which is not absorbed by the interior surface of the compartment wherein the position of the movable element within the interior of the compartment corresponds to the intensity of the light within the compartment and further wherein the first lens is located between the sensor and the interior of the compartment.