The Streaming Current Detector: A Quantitative Model

moves up and down. These charged particles are momenThe streaming current detector (SCD) is an instrument used tarily immobilized on the surfaces of the piston and the for continuous characterization of colloidal surface charge. It meacylinder. As the fluid motion forces mobile counterions in sures the alternating current generated by mobile countering when the double layer past these immobile particles, half-reactions charged material momentarily adheres to cylinder and piston walls at the electrodes generate the streaming current as an alterwhile the piston reciprocates. The utility of the SCD for coagulant nating current which is directly related to the charge on control is generally accepted, as evidenced by the estimated one the particles (3, 10). Electrical circuitry capable of phasethousand units in service in North America. However, one drawsensitive amplification and rectification of the current can back to this device has been the lack of an exact quantitative model