Contactless transmission of measurement information between sensor and conditioning electronics

Contactless transmission can be, in a lot of cases, a good answer when the measurement environment has characteristics unsuitable for the classical cable-transmission. In this article the contactless transmission problem is analyzed also when the distance between readout circuit and sensor circuit changes. A new measurement method that comprise also the evaluation of the distance is proposed. A parameter, that has a very little sensitivity to sensing capacitance and high sensitivity to the distance, is identified. The measurement method has been tested in the laboratory and the experimental results are reported.