A planar applicator for measuring surface dielectric constant of materials

Wireless Sensing Based on RFID and Capacitive Technologies for Safety in Marble Industry Process Control

“…Capacitive sensors for marble [9] and more complex ultrasound-or georadar-based systems [6,8,10] have been studied in the literature. However, their target is the �ne-grain analysis of the porosity and defects of stone materials (e.g., measuring the dielectric permittivity variations) in a controlled working environment (dry, clean, and with still stone samples) rather than the real-time detection of the presence of a marble slab during the working process inside an industrial machine.…”

“…To address some issues of the currently used and of other proposed slab detection techniques, this section of the work proposes novel capacitive sensors for the detection of stone samples during the industrial process, inside and outside the machine, and by means of contactless and low-complexity devices. Indeed, as reported in Table 1, the stone samples used in the marble industry have relative dielectric permittivity in the range 5 to 30 [5,9,10] that can be used to reveal the presence of a stone sample being different from those of air ( = 1), water ( = 81), or plastic ( between 2 and 3). As mentioned in Section 2, capacitive sensors have been studied in the literature [9] but the solutions proposed are optimized for a �ne-grain analysis of the porosity and surface defects of the stone material in a controlled working environment (dry and clean) rather than the real-time detection of a marble slab in an industrial machine.…”

“…Indeed, as reported in Table 1, the stone samples used in the marble industry have relative dielectric permittivity in the range 5 to 30 [5,9,10] that can be used to reveal the presence of a stone sample being different from those of air ( = 1), water ( = 81), or plastic ( between 2 and 3). As mentioned in Section 2, capacitive sensors have been studied in the literature [9] but the solutions proposed are optimized for a �ne-grain analysis of the porosity and surface defects of the stone material in a controlled working environment (dry and clean) rather than the real-time detection of a marble slab in an industrial machine. Furthermore in [9] the realized sensor should be taken in contact with the stone sample with a controlled force of 1 N and the stone sample should be held in a �xed position.…”

“…As mentioned in Section 2, capacitive sensors have been studied in the literature [9] but the solutions proposed are optimized for a �ne-grain analysis of the porosity and surface defects of the stone material in a controlled working environment (dry and clean) rather than the real-time detection of a marble slab in an industrial machine. Furthermore in [9] the realized sensor should be taken in contact with the stone sample with a controlled force of 1 N and the stone sample should be held in a �xed position. �nstead the aim of our work is the contactless detection of the presence of stone samples moving on the conveyer belt and considering a real industrial environment characterized by the presence of mud, water, and stone residuals and is not intended to measure or give information about material properties (e.g., thickness, composition, unhomogeneousness, etc.…”

Modeling the electrostatic control over depth of the introduction of intelligent sensors into a polymer composite material

“…They require access to a sample only from one side due to coplanar electrodes and can provide for measuring the electrical properties of the sample in the immediate vicinity from the surface of the sensor [13][14][15]. In most cases, an impedance measuring circuit carries out the measurement with a certain frequency of excitation.…”