The instrument uses streaming current technology to produce a measurement of electrokinetic charge (ionic & colloidal) using a sample obtained from various points in the process (Headbox, Coated Broke, Machine Chest, Tray Water, etc..). The measurement cell of the ECA consists of a reciprocating teflon piston in a probe assembly. Particles and dissolved materials are attracted to the surfaces of the probe by Van Der
Waals forces. Ions of both an Anionic and Cationic Charge surround these particles. The motion of the piston generates shear forces, which causes these ions to migrate. Electrodes in the probe measure the flow of ions, inherently defined as an electrical current. The current is electronically processed and displayed on the touchscreen as the STREAMING CURRENT VALUE (SCV).. Charge demand is determined with polyelectrolyte titration to the isoelectric point.