Investigation of Heterogeneous Mixtures With Dual-Modality Transducers Fabricated Using Thick-Film Technology

Volume 1 ◽  
2004 ◽  
Author(s):  
Guangtian Meng ◽  
Artur J. Jaworski ◽  
T. Dyakowski ◽  
J. M. Hale ◽  
N. M. White

The work presented in this paper focuses on development of a dual modality sensor, for deployment within an oil and gas extraction plant to measure the composition of oil-water mixtures. The sensors combine ultrasonic and electrical measurement techniques. These are of course non-destructive, rapid, and can potentially provide an on-line industrial measurement. In addition, the combination of two techniques could potentially be reliable in a wider range of process conditions and could contain self-calibration features. The sensors used in the current study were manufactured using thick-film technology, which enables construction of multilayered structures of both conductive and non-conductive layers, some of which may exhibit piezoelectric properties for ultrasonic measurement purposes. These are later fired on a ceramic substrate to provide rugged sensors, capable of working in aggressive industrial environments. Experiments were conducted for mixtures of vegetable oil and saline water to investigate the feasibility of such dual dual-modality sensors. The time of flight of ultrasonic wave in pure liquids and heterogeneous mixtures was measured. It has been shown that the signal obtained from the transducers is sufficiently strong to warrant the measurement of the speed of sound in heterogeneous mixtures of oil and water. A study of the effects of oil concentration and temperature on the speed of sound has been conducted. A mathematical model has been tested, which relates the speed of sound to the volume fraction taking into account the reflection and refraction on the droplet interfaces. The experimental results subjected to linear regression agree very well with the theoretical predictions. The electrical measurement was conducted at three different frequencies. In general, the values of capacitance and conductance decrease with increasing oil percentage. In the middle oil percentages a discontinuity occurs in the decreasing trend. In the high oil percentages, the experimental results agree very well with theoretical predictions.

1988 ◽  
Vol 13 (1) ◽  
pp. 1-6 ◽  
Author(s):  
F. Müller ◽  
M. Wolf

Experimental results concerning the dependence of the sheet resistivity and the noise coefficient on the grain size and the volume fraction, respectively, of the metallic-like component in Bi2Ru2O7-based thick-film resistors are presented. The results are compared with current models for the electrical conduction mechanism in these resistors.


1980 ◽  
Vol 7 (1-3) ◽  
pp. 87-91 ◽  
Author(s):  
Gunnar Björklund ◽  
Lars Linde

In order to minimize drift in a thick film resistor both printing and trimming parameters have to be optimized carefully.With the aid of a linear theoretical model it is shown how the resistance drift in the bulk transition zone and terminals of the resistor can be calculated for both trimmed and untrimmed resistors.The theoretical results are used for optimization of laser trimmed high ohmic resistors. The experimental results are in good agreement with the theoretical predictions and confirm that thick film resistors can be optimized for low drift.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1734
Author(s):  
Erick Franieck ◽  
Martin Fleischmann ◽  
Ole Hölck ◽  
Larysa Kutuzova ◽  
Andreas Kandelbauer

We report on the cure characterization, based on inline monitoring of the dielectric parameters, of a commercially available epoxy phenol resin molding compound with a high glass transition temperature (>195 °C), which is suitable for the direct packaging of electronic components. The resin was cured under isothermal temperatures close to general process conditions (165–185 °C). The material conversion was determined by measuring the ion viscosity. The change of the ion viscosity as a function of time and temperature was used to characterize the cross-linking behavior, following two separate approaches (model based and isoconversional). The determined kinetic parameters are in good agreement with those reported in the literature for EMCs and lead to accurate cure predictions under process-near conditions. Furthermore, the kinetic models based on dielectric analysis (DEA) were compared with standard offline differential scanning calorimetry (DSC) models, which were based on dynamic measurements. Many of the determined kinetic parameters had similar values for the different approaches. Major deviations were found for the parameters linked to the end of the reaction where vitrification phenomena occur under process-related conditions. The glass transition temperature of the inline molded parts was determined via thermomechanical analysis (TMA) to confirm the vitrification effect. The similarities and differences between the resulting kinetics models of the two different measurement techniques are presented and it is shown how dielectric analysis can be of high relevance for the characterization of the curing reaction under conditions close to series production.


1969 ◽  
Vol 24 (10) ◽  
pp. 1449-1457
Author(s):  
H. Klingenberg ◽  
F. Sardei ◽  
W. Zimmermann

Abstract In continuation of the work on interaction between shock waves and magnetic fields 1,2 the experiments reported here measured the atomic and electron densities in the interaction region by means of an interferometric and a spectroscopic method. The transient atomic density was also calculated using a one-dimensional theory based on the work of Johnson3 , but modified to give an improved physical model. The experimental results were compared with the theoretical predictions.


1976 ◽  
Vol 22 (11-12) ◽  
pp. 791
Author(s):  
R. Naylor

Sign in / Sign up

Export Citation Format

Share Document