NEPHELOMETER

A nephelometer or the like is constructed with a light-integrating chamber opening into a sample-receiving test chamber, so light from a beam of light directed longitudinally through a test tube holding a sample of liquid to be tested, which light is transversely scattered by particles of matter within the liquid, will be received by such light-integrating chamber. Means for reflecting and diffusing the received light is provided within the light-integrating chamber, so the received light will, in effect, be conserved and stored for transmittal of a maximum amount thereof to light-detecting means. As preferably constructed, the light-integrating chamber is annular and concentrically surrounds and opens into the test chamber, the light reflecting and diffusing means being a circumferential, unpolished but reflective, machined wall surface backing the annular chamber and confronting the test chamber, and the light detecting means being one or more sensors exposed to light from the light-integrating chamber through one or more ports provided in the diffusely reflective wall surface. In this way, signals of normal intensity are obtained by a light beam of less intensity than normal, thereby reducing heat and resulting turbulence of the sample, and the light received by the detectors is more representative of conditions in the sample than is normally the case. Electronic circuitry is employed that gives linear current output proportional to the amount of light detected. Thus, direct read-out of light measurements are possible.