Optimal frequency range for the measurement of A.C. conductivity in aqueous solutions

Ferrara, Enzo; Callegaro, Luca; Durbiano, Francesca

doi:10.1109/imtc.2000.848840

Cited by 10 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To maximize this coupling effect, the components C1, R1 and R2 in the circuit were chosen such that the oscillation frequency at the sensor nominal resistance was around 600 Hz, following the analysis of the data presented in [23], [38], [40]. The oscillation frequency is measured using a counter input of a digital signal processor (dsPIC33F, Microchip Technology).…”

Section: Electrical Interfacementioning

confidence: 99%

A Soft Strain Sensor Based on Ionic and Metal Liquids

et al. 2013

View full text Add to dashboard Cite

Abstract-A novel soft strain sensor capable of withstanding strains of up to 100% is described. The sensor is made of a hyperelastic silicone elastomer that contains embedded microchannels filled with conductive liquids. This is an effort of improving the previously reported soft sensors that uses a single liquid conductor. The proposed sensor employs a hybrid approach involving two liquid conductors: an ionic solution and an eutectic gallium-indium alloy. This hybrid method reduces the sensitivity to noise that may be caused by variations in electrical resistance of the wire interface and undesired stress applied to signal routing areas. The bridge between these two liquids is made conductive by doping the elastomer locally with nickel nanoparticles. The design, fabrication, and characterization of the sensor are presented.Index Terms-Wearable sensors, microfluidics, strain measurement, ionic solution, eutectic gallium indium (eGaIn).

show abstract

Section: Electrical Interfacementioning

confidence: 99%

A Soft Strain Sensor Based on Ionic and Metal Liquids

et al. 2013

View full text Add to dashboard Cite

show abstract

“…In practice, frequency values between 1 kHz and 5 kHz considerably reduce the electrolytic saturation [28]. On the other hand, high-frequency values must be avoided to minimize the effect of the capacitance in parallel with the resistance of the electrolytic solution (R b ).…”

Section: Conductvity: Theoretical Backgroundmentioning

confidence: 99%

Battery-Less NFC Conductivity Sensor for Bovine Mastitis Detection in Farming 4.0

Lazaro,

Villarino,

Pacios

et al. 2024

IEEE Access

View full text Add to dashboard Cite

This work proposes a battery-less Near-Field Communication (NFC) milk conductivity sensor for the early-stage detection of bovine mastitis. A proof-of-concept prototype is designed, which is composed of a loop antenna, an NFC microchip, a microcontroller, a custom conductivity sensor and a temperature sensor. A mobile phone is used as a reader, which additionally provides energy to the sensor to power all the electronic components. Since milk conductivity is temperature-dependent, it is also important to measure the temperature. The prototype has a precision better than 2%, which is similar to that of commercial hand-held conductivity meters. Measurements of the conductivity of cows' milk are made to establish limits that allow healthy cows to be discriminated from those suffering from clinical or subclinical mastitis. To this end, the obtained results are analyzed through ANOVA. The reliability of the method can be improved when milk samples from each quarter are used in the classification. This low-cost device has great potential to be used as on-farm screening tool for the quick identification of bovine mastitis.

show abstract

“…The capacitive contribution, which is inversely correlated with the frequency of the oscillating field and the capacitance of the measuring cell, can be in turn minimized by increasing the electrodes-solution contact area. The choice of the right frequency of the applied field plays a role in reducing these parasitic effects; in order to better correlate the electrical measurements with the solution ionic content, an optimal frequency value must be selected according to the characteristics of the analyzed electrolyte and the measurement cell (Prentice, 1962;Ferrara et al, 2000). Moreover, the optimal frequency of the electrical current can reduce the electrolyte friction, a retarding effect on the motion of the ion caused by the asymmetry between the atmosphere and the central ion (Debye and Falkenhagen, 1928).…”

Section: Introductionmentioning

confidence: 99%