Influence of Electrical Parameters of a Thin-Layer Sensor on the Accuracy of Pressure Measurement in an EHD Contact

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Adam Wilczek
Keyword(s):  
Thin Layer ◽  
Measurement System ◽  
Pressure Measurement ◽  
Piezoelectric Properties ◽  
Current Source ◽  
Circuit Model ◽  
Active Part ◽  
Model Study ◽  
Measurement Signal ◽  
Piezoelectric Effects

This paper presents a model study of inductive, capacitive, and piezoelectric effects on the accuracy of pressure measurements in an EHD contact. Circuit and mathematical models of a thin-layer sensor and a measurement system were developed. It has been assumed that isolation layers of the sensor, deposited as SiOx (1 ≤ x ≤ 2) layers, have piezoelectric properties. The circuit model of the sensor contains a resistance, an electric capacitance, an inductance of a sensor’s circuit, and an ideal current source representing piezoelectric properties of isolating layers of the sensor. The circuit model of the measurement system forms a full measuring bridge with the thin-layer sensor in one of its branches. A derived equation for output voltage of the measurement bridge was used as a mathematical model of the measurement system. The investigations show that at inappropriate electric parameters of the measurement system, inappropriate shape of the sensor’s transducer and short transition time of the sensor through the contact zone, the capacitive, and piezoelectric effects have a significant impact on the accuracy of pressure measurement in the EHD contact. The transducer with an active part located along its connection edges (asymmetric transducer) and a transducer with the active part located in the middle of connections width (symmetric transducer) was tested. It was shown that in the case of the symmetric transducer, the pressure measurement signal change caused by the capacitive and piezoelectric effects, is much smaller than in the case of the asymmetric transducer.

The Influence of Construction Features of a Thin-Layer Sensor on Pressure Distributions Recorded in an Elastohydrodynamic Contact

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Adam Wilczek
Keyword(s):  
Thin Layer ◽  
Piezoelectric Properties ◽  
Active Part ◽  
Pressure Measurements ◽  
Rotation Direction ◽  
Pressure Distributions ◽  
Measurement Signal ◽  
Piezoelectric Effects ◽  
Signal Distortions ◽  
Different Shapes

This paper presents the experimental study of the construction features of a thin-layer sensor on the accuracy of pressure measurements in an EHD contact. Two common types of transducer shapes and isolating layers of the sensor, made of SiO are considered. The measurements were carried out on a two-disc machine, with the use of two mating lubricated steel cylindrical disks. On the outside surface of one of the discs, a pressure sensor was deposited with two transducers of different shapes, symmetric and asymmetric, located close to each other. The pressure transducer has an active part in the form of a layer contraction, and two wider parts of the layer serves as electrical leads (connections). In the symmetric transducer, the active part is located in the middle of the connections width and in the asymmetric transducer the active part is located along the edge of connections. In case of no current supply for the measurement bridge, the measurement signals from the sensor were observed. The occurrence of these signals indicated piezoelectric properties of the insulation layers of the sensor. The investigations showed that the shape of the transducer has a significant influence on the accuracy of pressure measurements. In the case of the asymmetric transducer, the measurement signal distortions caused by the piezoelectric effects and changes in the electric capacitance of the sensor were much larger than in the case of the symmetric transducer. Measurement signal courses coming from the asymmetric transducer were significantly influenced by the transition velocity of the sensor trough the contact, by the value of the current supplying the measurement bridge and by the rotation direction of the disc with the sensor.

1997 William J. Stickel Bronze Award. Comparison of strategies for reducing pressure at the site of neuropathic ulcers

1997 ◽  
Vol 87 (10) ◽  
pp. 466-472 ◽  
Author(s):  
JG Fleischli ◽  
LA Lavery ◽  
SA Vela ◽  
H Ashry ◽  
DC Lavery
Keyword(s):  
Diabetes Mellitus ◽  
Measurement System ◽  
Pressure Measurement ◽  
Scientific Data ◽  
Consistent Pattern ◽  
Great Toe ◽  
The Third ◽  
System Data ◽  
Pressure Measurement System ◽  
Neuropathic Ulcers

Few scientific data are available on the effectiveness of commonly used modalities for reducing pressure at the site of neuropathic ulcers in persons with diabetes mellitus. The authors' aim was to compare the effectiveness of total contact casts, half-shoes, rigid-soled postoperative shoes, accommodative dressings made of felt and polyethylene foam, and removable walking casts in reducing peak plantar foot pressures at the site of neuropathic ulcerations in diabetics. Using an in-shoe pressure-measurement system, data from 32 midgait steps were collected for each treatment. There was a consistent pattern in the devices' effectiveness in reducing foot pressures at ulcer sites under the great toe and ball of the foot. Removable walking casts were as effective as or more effective than total contact casts. Half-shoes were consistently the third most effective modality, followed by accommodative dressings and rigid-soled postoperative shoes.

scholarly journals Design and Development of a Nonintrusive Pressure Measurement System for Pipeline Monitoring

2014 ◽  
Vol 5 (3) ◽  
pp. 04014001 ◽  
Author(s):  
A. M. Sadeghioon ◽  
Robert Walton ◽  
David Chapman ◽  
Nicole Metje ◽  
Carl Anthony ◽  
...  
Keyword(s):  
Measurement System ◽  
Pressure Measurement ◽  
Design And Development ◽  
Pipeline Monitoring ◽  
Pressure Measurement System

Evaluating the suitability of thick-film TiO2 capacitors for use in a wireless pressure measurement system

2006 ◽  
Vol 26 (5-7) ◽  
pp. 1077-1081 ◽  
Author(s):  
K. Arshak ◽  
D. Morris ◽  
A. Arshak ◽  
O. Korostynska ◽  
E. Jafer
Keyword(s):  
Thick Film ◽  
Measurement System ◽  
Pressure Measurement ◽  
Pressure Measurement System

Experimental Study of Multiphase Flow in Cold Box Core Process

2000 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt
Keyword(s):  
Experimental Study ◽  
Multiphase Flow ◽  
Measurement System ◽  
Pressure Measurement ◽  
Test Specimen ◽  
Filling Process ◽  
Cold Box ◽  
Pressure Measurement System ◽  
Sand Deposition

Abstract The results of experimental study of pressure variations inside core box during resin bonded sand filling process are reported. The test core specimens were produced using Laempe® Test Specimen Curing Machine L 1. A special pressure measurement system was designed and built with safety and portability requirements of the foundry environment. Special experiments were conducted to establish the effect of sand deposition on vent permeability.

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