A low-cost circuit for high-value resistive sensors varying over a wide range

摘要: In this paper, a low-cost interface for high-value resistive sensors ranging from kΩ to GΩ is presented. The proposed circuit acts as 'resistance-to-period converter' and overcomes limits of previously developed solutions due sensor parasitic capacitance. Particularly, estimates resistance over six orders magnitude without changing any scaling factor able quantify capacitance, in the order pF. Estimation errors, real electronic components, are taken into account. Experimental results, obtained by realized prototype, show good resolution repeatability, always better than 0.05%. Thermal effects have been considered experimentally evaluated θ = 10 °C 60 °C.