An optical chamber assembly of a detection device comprising: a light ring for supporting three light sources (48a, 48b, 48c) and a light receiver; an optical cover defining an interior chamber of the optical chamber assembly; and an intermediate component disposed between the light ring and the optical cover, wherein the intermediate component optically couples the three light sources and the light receiver with the interior chamber; characterized in that the light ring is formed from a first material, the intermediate component is formed from a second material, and the optical cover is formed from a third material, the first material, the second material, and the third material being different; in that the light receiver is disposed to receive light that is emitted by one of the three light sources and that is then reflected from the interior chamber within the optical chamber assembly by an ambient material toward the light receiver, wherein the first light source and the second light source are selected to emit light having different wavelengths and the three light sources are arranged such that the third light source is arranged at an angle to the light emitted by the first and second light sources (48a, 48b); and in that the optical cover includes an end piece and a plurality of individual side members extending from the end piece, wherein each of the plurality of side members is substantially identical in shape, the side members are spaced equidistantly about the periphery of the end piece, and the side members are labyrinth-like in shape and are offset from one another by a distance such that a clearance is formed between adjacent side members. a light ring for supporting three light sources (48a, 48b, 48c) and a light receiver; an optical cover defining an interior chamber of the optical chamber assembly; and an intermediate component disposed between the light ring and the optical cover, wherein the intermediate component optically couples the three light sources and the light receiver with the interior chamber; characterized in that the light ring is formed from a first material, the intermediate component is formed from a second material, and the optical cover is formed from a third material, the first material, the second material, and the third material being different; in that the light receiver is disposed to receive light that is emitted by one of the three light sources and that is then reflected from the interior chamber within the optical chamber assembly by an ambient material toward the light receiver, wherein the first light source and the second light source are selected to emit light having different wavelengths and the three light sources are arranged such that the third light source is arranged at an angle to the light emitted by the first and second light sources (48a, 48b); and in that the optical cover includes an end piece and a plurality of individual side members extending from the end piece, wherein each of the plurality of side members is substantially identical in shape, the side members are spaced equidistantly about the periphery of the end piece, and the side members are labyrinth-like in shape and are offset from one another by a distance such that a clearance is formed between adjacent side members.