Contactless Interrogation System for Capacitive Sensors with Time-Gated Technique†
AbstractThis paper presents a measurement technique and system for the contactless interrogation of capacitive sensors via electromagnetic coupling. The interrogation unit employs a primary coil to periodically excite the capacitive sensor connected to a secondary coil forming an LC resonant circuit. When the excitation to the primary coil is switched off the damped response of the LC circuit is detected. As a fundamental advantage compared to techniques based on reflected impedance, this approach ensures that the readout frequency is to first order independent of the interrogation distance between the two coils. The system has been tested with reference capacitors and with a capacitive liquid level sensor. The experimental results are in a good agreement with theoretical expectations and show a sensitivity of about −23 kHz/pF at 5.4 MHz and the possibility to operate with interrogation distances up to few centimeters.
Share & Cite This Article
Masud, M.; Baù, M.; Demori, M.; Ferrari, M.; Ferrari, V. Contactless Interrogation System for Capacitive Sensors with Time-Gated Technique. Proceedings 2017, 1, 395.
Masud M, Baù M, Demori M, Ferrari M, Ferrari V. Contactless Interrogation System for Capacitive Sensors with Time-Gated Technique. Proceedings. 2017; 1(4):395.Chicago/Turabian Style
Masud, Mehedi; Baù, Marco; Demori, Marco; Ferrari, Marco; Ferrari, Vittorio. 2017. "Contactless Interrogation System for Capacitive Sensors with Time-Gated Technique." Proceedings 1, no. 4: 395.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.