Contactless transmission of measurement information between sensor and conditioning electronics

In many cases, contactless transmission can be a solution to applications where the measurement environment has characteristics that are unsuitable for the classical cable transmission. In this paper, the contactless transmission problem is analyzed when the distance between the readout and the sensor circuits changes. A model of the system, which considers the effect of the parasitic capacitance and the change of coupled and leakage fluxes, is proposed. A simulation of the theoretical analysis on the developed model shows that one frequency is more sensitive to the transducer capacitance and has no dependence on stray capacitance. A parameter that has very little sensitivity to sensing capacitance and high sensitivity to distance is identified. The measurement method has been tested in the laboratory, and the relative experimental results are reported.