摘要:
In the present invention, the test reference electrode used for voltammetric analysis of a plating bath is calibrated relative to the zero-current point between metal plating and stripping at a rotating platinum disk electrode in the plating bath supporting electrolyte. This calibration is readily performed during the normal course of cyclic voltammetric stripping (CVS) or cyclic pulse voltammetric stripping (CPVS) plating bath analysis the need for additional instrumentation or removal of the test reference electrode from the analysis equipment. Automatic calibration of the reference electrode enabled by the present invention, saves labor, time and expense, and minimizes errors in the plating bath analysis.
摘要:
A conductivity measurement system provides one or more DC pulses to first and second electrodes submerged in an aqueous solution such as, for instance, the wash water of an industrial dishwasher. The voltage at the first electrode is measured at a sequence of at least three predetermined times after initiation of one of the DC pulse. A non-linear curve fitting function is applied to the sequence of at least three voltage measurements to calculate the voltage at the first electrode at the beginning of the DC pulse(s), commonly denoted as being at time t=0. The resulting calculated voltage at time t=0 is then used to calculate the conductivity of the solution, and/or to control operation of the a chemical dispenser, and/or to perform another predetermined system analysis or system control function. In addition, the difference between two of the measured voltages, such as the first and second measured voltages, is compared to a predetermined threshold value to determine whether the electrodes are so contaminated that polarization compensation is no longer feasible, thereby signaling that the electrodes should be cleaned or replaced.
摘要:
A method for measuring a target constituent of an electroplating solution using an electroanalytical technique is set forth in which the electroplating solution includes one or more constituents whose by-products skew an initial electrical response to an energy input of the electroanalytical technique. The method comprises a first step in which an electroanalytical measurement cycle of the target constituent is initiated by providing an energy input to a pair of electrodes disposed in the electroplating solution. The energy input to the pair of electrodes is provided for at least a predetermined time period corresponding to a time period in which the electroanalytical measurement cycle reaches a steady-state condition. In a subsequent step, an electroanalytical measurement of the energy output of the electroanalytical technique is taken after the electroanalytical measurement cycle has reached the steady-state condition. The electroanalytical measurement is then used to determine an amount of the target constituent in the electroplating solution. An automatic dosing system that includes the foregoing method and/or one or more known electroanalytical techniques in a close-loop system is also set forth.
摘要:
A method for measuring a target constituent of an electroplating solution using an electroanalytical technique is set forth in which the electroplating solution includes one or more constituents whose by-products skew an initial electrical response to an energy input of the electroanalytical technique. The method comprises a first step in which an electroanalytical measurement cycle of the target constituent is initiated by providing an energy input to a pair of electrodes disposed in the electroplating solution. The energy input to the pair of electrodes is provided for at least a predetermined time period corresponding to a time period in which the electroanalytical measurement cycle reaches a steady-state condition. In a subsequent step, an electroanalytical measurement of the energy output of the electroanalytical technique is taken after the electroanalytical measurement cycle has reached the steady-state condition. The electroanalytical measurement is then used to determine an amount of the target constituent in the electroplating solution. An automatic dosing system that includes the foregoing method and/or one or more known electroanalytical techniques in a close-loop system is also set forth.
摘要:
The Applicant's invention comprises an apparatus and method for determining the amount of one or more components in a pulping liquor. At a first electrode, a varying voltage is supplied in a voltage range including the half-wave potential of each component of a liquor to be measured, and accounting for variations in the half-wave potential caused by changing process parameters. At a second electrode, which is roughly ⅓ to ¼ the size of the first electrode, the derivative of current intensity is monitored near the known half-wave potential for the various liquor components. Using curve-fitting means, the derivative of current intensity and selected other process condition data is used to determine concentrations of the various liquor components.
摘要:
A conductivity measurement system provides one or more DC pulses to first and second electrodes submerged in an aqueous solution such as, for instance, the wash water of an industrial dishwasher. The voltage at the first electrode is measured at first and second predetermined times after initiation of DC pulse(s). Linear regression of the first and second measured voltages is used to calculate the voltage at the first electrode at the beginning of the DC pulse(s), i.e., at time t=0. The resulting voltage at time t=0 is then used to calculate the conductivity of the solution, thereby compensating for the effects of polarization. Further, the difference between the respective first and second measured voltages is compared to a predetermined threshold value to determine whether the electrodes are so contaminated that polarization compensation is no longer feasible, thereby signaling that the electrodes should be cleaned or replaced.