A distance compensated telemetric humidity sensor based on the parasitic capacitance variation

In this article a telemetric system for relative-humidity measures is proposed. The contactless transmission problem is analyzed also when the distance between readout circuit and sensing circuit changes. Three hydrophilic polymers are deposited on parasitic capacitance of sensing system. The sensitivities to the relative humidity and distance are calculated. The measurement method has been tested in the laboratory and the experimental results are reported.