DEVICE FOR POTENTIOSTATIC AND GALVANOSTATIC MEASUREMENTS WITH AUTOMATIC COMPENSATION FOR IR ERROR

摘要

FIELD: measurement technology, electrochemical measurements corrosion measurement included in oil and gas industries, chemical, metallurgical and other branches of industry. SUBSTANCE: invention makes it possible to compensate for measurement error of electrode potential caused by drop of voltage in volume of electrolyte between comparison and working electrodes, that is, provides for increased accuracy of measurement of potential. Compensation of error is realized by mechanism of currentless measurement of electrode potential. The device has pulse generator 5, current interrupter 4, retrieval and storage unit 8. Voltage proportional to specified value of electrode potential or polarization current is applied under potentiostatic and galvanostatic operation modes to noninverting input of differential amplifier 20 and measured values of potential or current are applied to its inverting input. Output voltage of differential amplifier 20 is applied through current interrupter 4 to auxiliary electrode 2 and changes current flowing through electrochemical cell 1 so that difference of voltages across inputs of differential amplifier 20 is minimal. Currentless measurement of electrode potential is realized by interruption of current and memorization of potential value in retrieval and storage unit 8 at time moments when current does not flow through cell 1. Synchronous operation of current interrupter 4 and retrieval and storage unit 8 is ensured by pulse generator 5. EFFECT: increased accuracy of measurement of potential. 1 dwg