Patent ID: 7142299

Claim:
A turbidity measuring system for measuring a sample liquid comprising: a chamber with at least one inlet and at least one outlet; a cover for covering the chamber; a sensor unit mounted on the cover, said sensor unit including: a watertight housing having a tilted bottom with respect to a sample liquid surface of the sample liquid, said watertight housing being placed below the liquid surface in the chamber when the sensor unit is in use; a light source; a first light focusing device for focusing a light emitted from the light source and passing therethrough into the liquid sample; a second light focusing device for collecting at least one scattered light resulted form the light passing into the liquid sample; a light detector for receiving the collected light thereby generating electronic signals; and a processor for converting the electronic signals into turbidity measuring units, wherein said watertight housing has two cavities for accommodating the light source and the light detector therein respectively, and two cylindrically-shaped channels for accommodating the first and second focusing devices therein respectively, the cylindrically-shaped channels are tilted away from the tilted bottom of said watertight housing at an angle symmetrically, and each of the cavities has a flat end tilting relatively to a cylinder axis thereof with the angle so as to be in parallel with the tilted bottom of said watertight housing.