Electro-optic liquid sensor enabling in-liquid testing having a light source providing a plurality of intensities for assessing an operational state of the sensor

1. A sensor, comprising:

a light source;

a light detector;

a prism; and

a reflective optical member,

wherein the reflective optical member is arranged to reflect light emitted by the light source to the light detector and the light source is configured to provide light at a plurality of intensities for assessing an operational state of the sensor.

2. The sensor of claim 1 , wherein the light source is configured to emit light in the infrared or near-infrared portion of the electromagnetic spectrum.

3. The sensor of claim 1 , wherein the prism is arranged so as to reflect light emitted by the light source to the light detector when liquid is not present between the light source and the optical member.

4. The sensor of claim 1 , wherein the prism is disposed between the light source and the optical member and between the optical member and the light detector.

5. The sensor of claim 1 , wherein the plurality of intensities includes a first intensity, a second intensity, and a third intensity; and the first intensity, the second intensity, and the third intensity are different from each other.

6. The sensor of claim 5 , wherein the second intensity is configured to ensure that light from the light source will have sufficient energy to propagate from the light source through liquid to the reflective optical member and back to the light detector.

7. The sensor of claim 1 , including a housing, wherein the light source, the light detector, the prism, and the optical member are disposed within the housing, and the optical member has less-than-complete reflectivity.

8. The sensor of claim 7 , wherein the housing comprises two or more ports configured to admit liquid into the housing.