Patent ID: 8345248

Claim:
An optical cavity enhanced turbidimeter comprising: an optical source configured to emit a beam having a predetermined wavelength; a vessel having a liquid sample; an optical cavity containing first and second highly reflective mirrors facing each other, the vessel being disposed between the first and second mirrors, the first mirror to accept and allow the beam to repeatedly pass through the liquid sample and to the second mirror, the second mirror to accept and allow the beam to repeatedly pass through the second mirror to an optical detector; the optical detector configured to measure an intensity of a beam output from the optical cavity after the beam passes through the liquid sample repeatedly, where the optical detector has a sufficiently quick response time to measure the intensity of exponentially attenuating light provided by the beam output upon passing through the liquid sample; a controller configured to calculate an attenuation rate of the beam output, where the turbidity of the liquid sample is determined by the scattering level of light having a wavelength not corresponding to the absorption line of the target material in the liquid sample.