초록 ▼

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

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.

대표청구항 ▼

[ We claim:] [1.]1. A method of measuring representations of the electrical conductivity of an aqueous solution which compensates for polarization, said method comprising the steps of:(a) providing first and second electrodes within said solution;(b) generating, using a measurement circuit, a DC pul

[ We claim:] [1.]1. A method of measuring representations of the electrical conductivity of an aqueous solution which compensates for polarization, said method comprising the steps of:(a) providing first and second electrodes within said solution;(b) generating, using a measurement circuit, a DC pulse to induce a current between said first and second electrodes;(c) sampling the voltage at said first electrode at a first predetermined time interval after the generation of said DC pulse and generating a first voltage value in response thereto;(d) sampling the voltage at said first electrode at a second predetermined time interval after the generation of said DC pulse and generating a second voltage value in response thereto;(e) calculating, using linear regression and said first and second voltage values, the voltage at said first electrode contemporaneous with the generation of said DC pulse and generating a third voltage value in response thereto;(f) producing, in response to said third voltage, a first signal representing the conductivity of said solution.