Dielectrometry measurements of moisture dynamics in oil-impregnated pressboard

Sheiretov, Yanko; Zahn, M.

doi:10.1109/elinsl.1994.401474

Cited by 25 publications

(25 citation statements)

References 3 publications

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“…The relative complex permittivity can be measured as a function of frequency using dielectric spectroscopy (Von Hippel, 1954a). Dielectric spectroscopy has been used for comparing different petroleum fractions (Folgero, 1998;Tjomsland, et al, 1996), sensing moisture dynamics in oil impregnated pressboard (Sheiretov & Zahn, 1995), and monitoring of moisture content and insulation degradation in oil transformers (Koch & Feser, 2004).…”

Section: Pagementioning

confidence: 99%

Dielectric Spectroscopic Sensor for Particle Contaminant Detection in Hydraulic Fluids

2014

2014 ASABE Annual International Meeting

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Particulate contamination of hydraulic fluids is one of the major causes of mechanical wear of hydraulic components resulting in system inefficiency and failure. Potential failures of hydraulic systems could be avoided through continuously monitoring the condition of the fluid. A practical contaminant sensor was developed to estimate the level of particulate contamination in hydraulic fluids. The sensor was designed to be installed on vehicle and provide in-line measurements of contaminated hydraulic fluid. The sensor used dielectric spectroscopy for measuring contaminants. To investigate the performance of the dielectric sensor two tests were performed with different diameter central rods using iron particles as hydraulic contaminants. A hydraulic test circuit was built and a methodology was developed for the tests. An eight-channel particle counter was used for calibration of the dielectric sensor. PLS models were developed to investigate the relationship between dielectric spectra and iron particle counts. The RMSEC and RMSECV for the sensor with a central rod diameter of 6.35 mm were 1.1ISO 4406 scale numbers and 1.39 scale numbers respectively. For a 17.7 mm diameter rod, the respective values were 0.62 and 0.77. The sensor shows good potential estimate of the cleanliness level of hydraulic fluid mixed with iron contaminants.

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Section: Pagementioning

confidence: 99%

Dielectric Spectroscopic Sensor for Particle Contaminant Detection in Hydraulic Fluids

2014

2014 ASABE Annual International Meeting

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“…This relative complex permittivity of the material can be measured as a function of frequency using dielectric spectroscopy (Von Hippel, 1954a). Dielectric spectroscopy has been used for comparing different petroleum fractions (Folgero, 1998;Tjomsland, et al, 1996), sensing moisture dynamics in oil impregnated pressboard (Sheiretov & Zahn, 1995), and monitoring of moisture content and insulation degradation in oil transformers (Koch & Feser, 2004).…”

Section: Introductionmentioning

confidence: 99%

Dielectric Spectroscopic Aerosol Sensing in the Compressed Air Stream

Kshetri¹,

Steward²,

Birrell³

2016

2016 ASABE International Meeting

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Contamination of compressed air can reduce its utility and lead to costly failure of pneumatic components. Monitoring the presence of contaminants in the air could provide early warning to take measures that could retain pneumatic system usefulness. The sensing of contaminants in a compressed air stream using dielectric spectroscopy has good potential for a viable commercial sensor for pneumatic systems based on the differences in dielectric properties between air and common contaminants such as metal, silicon, and water condensate. Oil mist, while not a contaminant, is required for lubricating pneumatic components, so its presence is important. Two tests were performed using a dielectric sensor capable of spectroscopic measurement to investigate the efficacy of dielectric spectroscopy in detecting the presence of liquids (water and oil) in compressed air. The first test used deionized water, and the second test used a light lubricant oil (Sunoco Sunvis 932, Sunoco, PA). Industrial spray nozzles were used to atomize these liquids, which were then entrained in a compressed airstream and passed through the dielectric sensor. Visualization of spectroscopic measurements and their transformation using principal component analysis (PCA) showed that the sensor has potential to differentiate the presence and absence of liquid droplets in compressed airstream. This separation of two cases based on the spectroscopic data suggests that dielectric spectroscopy could be used to detect these two liquids in the compressed airstream.

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“…The goal of this paper is to present results of simulations and measurements that are directly applicable to the stair-step inversion algorithm. In this algorithm, dielectric properties close to the sensor are estimated first, and then used to estimate properties of consecutive layers [4], [7]. This paper treats issues related to sensitivity and accuracy of parameter estimations from interdigital dielectrometry measurements.…”

mentioning

confidence: 99%

“…Work in this area had been conducted as early as in the 1960s [3]. Since then, a number of theoretical and experimental investigations have contributed to different aspects of this technology, including electric field modeling [4], [5], industrial and scientific applications [6], [7], design optimization [8], and parameter estimation [9].…”

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confidence: 99%

Uncertainty in multiple penetration depth fringing electric field sensor measurements

Mamishev

Cantrell

et al. 2002

IEEE Trans. Instrum. Meas.

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Abstract-Measurement of multilayer material properties with fringing electric field dielectrometry sensors requires the processing of terminal admittance data from multiple electrode pairs. The choice of the algorithmic approach for data analysis is critical because of a high sensitivity to small measurement uncertainties. While individual channel uncertainties are usually within a reasonable instrumentation range, measurement of properties of multiple material layers fails unless special techniques are used to prevent numerical instabilities. This paper demonstrates the mechanism of uncertainty in a successive stair-step property estimation in which the estimates of one layer's properties are used to estimate the subsequent layer's properties. Three-wavelength measurements of dielectric permittivity and conductivity illustrate the problem in two-layer experimental setups. Limitations of the stair-step approach and possible future improvements are discussed.

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Dielectrometry measurements of moisture dynamics in oil-impregnated pressboard

Cited by 25 publications

References 3 publications

Dielectric Spectroscopic Sensor for Particle Contaminant Detection in Hydraulic Fluids

Dielectric Spectroscopic Sensor for Particle Contaminant Detection in Hydraulic Fluids

Dielectric Spectroscopic Aerosol Sensing in the Compressed Air Stream

Uncertainty in multiple penetration depth fringing electric field sensor measurements

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