ELECTROSTATIC METHOD OF MEASURING THE MOISTURE CONTENT OF LOOSE SUBSTANCES AND DEVICE INTENDED FOR ITS REALIZATION Russian patent published in 1997 - IPC

FIELD: measurement technology. SUBSTANCE: method consists in measuring the potential difference between measuring electrode immersed in substance under check and supporting electrode. Measurement is performed in pulse mode. Every measurement cycle includes pulse charging of electrodes, measurement of potential difference between electrodes and pulsed removal of charge from electrodes and from substance being checked. In every subsequent cycle charge of electrodes is increased by fixed value. Measurement cycles are repeated till constant value of potential difference is obtained. Moisture content of substance under check is determined by the above-indicated potential difference with due regard for calibration curve. Device for measuring the moisture content has two electrodes 2,3, clock-pulse generator 15, high-frequency oscillation generator 17, switching pulse forming unit 16 three outputs of which are connected to control inputs of electronic switches connected to two channels of direct current amplification. At input, amplification channels are connected to electrodes 2,3, respectively, and at output they are connected to input of differential amplifier 12 which is in its turn connected to analog-to-digital converter 13 and to indicator 14. Every channel has first electronic switch 20-23, first follower 4, 5, second electronic switch 6, 7, capacitor 10, 11, second follower 8, 9, and third electronic switch 18, 19. EFFECT: higher measurement accuracy. 3 cl, 2 dwg