Sensor Interface for Multimodal Evaluation of Capacitive Sensors

7th Sensors & their Applications

Schlegl, Thomas^1 ; Zangl, Hubert^1

Institute for Electrical Measurement and Measurement Signal Processing, Graz University of Technology, Inffeldgasse 23/II, 8010 Graz, Austria^1

关键词: Differential mode;    Experimental investigations;    High robustness;    Proximity sensing;    Sensor interface;    Sensor surfaces;    Single-ended;    State of the art;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/450/1/012018/pdf
DOI  :  10.1088/1742-6596/450/1/012018

来源: IOP

【 摘 要 】

Capacitive proximity sensing can be done in different modes. The single ended mode usually offers a higher signal to noise ratio (SNR) and-in conjunction with active guarding-high robustness. However, it can be blind for objects with low permittivity close to the sensor surface. The differential mode usually has a worse SNR but has the capability to detect objects in situations where the single ended mode is blind. Thus, we propose a measurement circuitry to combine both modes. It is compared to state of the art sensors and the benefits of this approach are demonstrated by means of experimental investigations.