A new time-domain measurement method for determining the capacitance and resistance values of lossy relative humidity capacitive sensors is presented. The method is based on a direct sensor-to-microcontroller interface for microcontrollers with internal analog comparators and timers. The interface circuit consists only of four reference resistors (two reference resistors if a microcontroller includes a voltage reference source), a given sensor and a microcontroller. A systematic error correction algorithm based on a correction dictionary and the M-multiple measurement approach are also proposed in the paper. Experimental investigations were carried out using a prototype device based on an 8-bit ATXmega32A4 microcontroller. The experimental research confirmed that the relative errors of measurement of capacitance introduced by the interface circuit are less than 0.71% (for capacitance values 100 – 286 pF), and the relative errors of measurement of resistance are less than 0.74% (for resistance values 1 – 10 MOhm).
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Additional information
- DOI
- Digital Object Identifier link open in new tab 10.1016/j.measurement.2020.108702
- Category
- Publikacja w czasopiśmie
- Type
- artykuły w czasopismach
- Language
- angielski
- Publication year
- 2021
