20.500.12556/DKUM-92354 Multiple quartz crystals connected in parallel for high-resolution sensing of capacitance changes We present a new highly sensitive, low-value capacitance sensor method that uses multiple quartz crystals connected in parallel inside the oscillator. In the experimental setup, the measured (sensible) reactance (capacitance) is connected in parallel to the total shunt capacitance of the quartz crystals, oscillating in the oscillator. Because AT-cut crystals have a certain nonlinear frequency– temperature dependence, we use the switching mode method, by which we achieve a temperature compensation of the AT-cut crystals’ frequency–temperature characteristics in the temperature range between 0–50 ◦C. The oscillator switching method also compensates for any other influences on the frequency of the oscillator, such as ageing of the crystals and oscillator elements, supply voltage fluctuations, and other parasitic impedances in the oscillating circuit. Subsequently using two 50-ms-delayed switches between the measuring and reference capacitors, the experimental error in measuring the capacitance is lowered for measurements under a dynamic temperature variation in the range of 0–50 ◦C. The experimental results show that the switching method, which includes a multiple quartz connection and high-temperature compensation improvement of the quartz crystals’ characteristics, enables a sub-aF resolution. It converts capacitance changes in the range 10 zF–200 fF to frequencies in the range 4 kHz–100 kHz. multiple quartz crystals in parallel quartz capacitive sensing method temperature compensation switching mode method večkvarčni kristali občutljive metode temperaturna kompenzacija true false true MDPI AG Angleški jezik Slovenski jezik https://www.mdpi.com/journal/sensors © 2022 by the author Članek v reviji 2025-04-01 10:08:04 2025-04-01 10:08:04 2025-04-02 03:09:44 0000-00-00 00:00:00 2022 0 0 15 str. iss. 13 Vol. 22 3 July 2022 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2022-06-21 2022-06-30 2022-07-03 621.317 113633795 10.3390/s22135030 1424-8220 sensors-22-05030-v2.pdf sensors-22-05030-v2.pdf 1 1681B466D3BE0D729906B00D392CE45C 3a0c14b4011d0404630924d13f2508975336e2cab1227353960a2c1db14a4a79 b3863535-0ed0-11f0-811a-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=189888 https://www.mdpi.com/1424-8220/22/13/5030 1 70c44b36-0ed0-11f0-811a-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=189887 Fakulteta za elektrotehniko, računalništvo in informatiko 0 0 0