Patent ID: 6942782

Claim:
A method of measuring the deposit forming propensity of a continuously flowing fluid having a bulk pH of about 1 to about 12 comprising measuring the rate at which deposit forms on a quartz crystal microbalance having a top side comprising a working electrode in contact with the fluid and the other side isolated from the fluid, wherein the pH of the fluid proximate to the microbalance is controlled electrochemically,via a galvanostatic system, at about 1 to about 14 by applying to the working electrode a cathodic current of about −0.001 to about −100 mA/cm 2 or an anodic current of from about 0.001 to about 100 mA/cm 2 and wherein the working electrode is coated with or made of a conductive material on which the rate of hydrogen gas evolution is insufficient to hinder precipitation of scale onto the working electrode under the electrochemical polarization required to precipitate the deposit from the fluid.