METHOD AND DEVICE FOR DETERMINING HYDROGEN ION CONCENTRATION Russian patent published in 2001 - IPC

FIELD: measurement technology. SUBSTANCE: proposed method involves determination of hydrogen ion concentration (pH) by measuring electrical characteristics of medium by steady state potential of signal under measurement corresponding to physical and chemical composition of medium using high-impedance electrodes for the purpose. Signal is recorded by time interval between start of measurement and threshold value attained in each cycle. In the process signal under measurement is shaped from dynamic potential difference across measuring and comparing electrodes of measuring cell due to accumulation of ions across measuring electrode. Cycle initiation is organized upon zeroing signal under measurement as soon as its amplitude rises to its threshold value by end of preceding cycle. Device implementing proposed method has measuring cell, amplifier, calculator, analog-to-digital converter, and switch designed to couple output of measuring cell with amplifier input. Amplifier output is connected through analog-to-digital converter over data bus to calculator built around personal computer which is connected over control bus to control input of switch. EFFECT: enhanced measurement speed, enlarged check-up range at preset metrological characteristics. 2 cl, 4 dwg, 1 tbl