Patent ID: 7047806

Claim:
A liquid level gage, comprising: a housing having a first end and a second end; a liquid column connected to the first end of the housing, the liquid column including a plurality of liquid column bodies and a plurality of port assemblies, wherein a pair of port assemblies is connected to each liquid column body; and an illuminator connected to the second end of the housing, the illuminator including a plurality of directed light source assemblies, wherein: half of the directed light source assemblies emit a first color light and half of the directed light sources emit a second color light, a pair of bi-color directed light source assemblies corresponds to each liquid column body and pair of port assemblies, and each pair of bi-color directed light source assemblies is oriented with respect to the corresponding liquid column body and pair of port assemblies in such a way that the first color light passes through the corresponding liquid column body and pair of port assemblies when a liquid is present in the corresponding liquid column body and the second color light passes through the corresponding liquid column body and pair of port assemblies when a non-liquid is present in the corresponding liquid column body.