Ships and marine technology � Verification method for portable power measurement using a strain gauge

2018 ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. e17-e23 ◽  
Author(s):  
S. M. Vanyeyev ◽  
D. V. Miroshnichenko ◽  
T. S. Rodymchenko ◽  
M. Protsenko ◽  
D. V. Smolenko

The need for power measurement transmitted by the running shaft has led to the need for using devices for measuring torque on the shaft. Of particular importance is the power measurement on high-speed machines, wherein some cases conventional measurement systems are either unsuitable or have low accuracy. Currently, data measuring systems are widely used in the researches of turbomachines. They allow to receive, process, transmit, store and display measurement data. Their application is relevant in relation to the priority of experimental study and subsequent modeling of characteristics and performance factors of expansion machines. The purpose of this research is a design and generation of the data measuring system for measuring torque on the running shaft of vortex expansion machines using a non-contact torsional dynamometer (strain-gauge clutch). The research has considered the results of the development of data measuring system, performed a theoretical analysis and presented the results of the practical application of the non-contact strain-gauge dynamometer designed for torque measurement on the shaft of low-power expansion machines when operating under bench test conditions. Has dealt with the problems of development, calibration. Keywords: data measuring system, torque, coupling, resistive-strain sensor, vortex expansion machine.


Ultrasonics ◽  
1980 ◽  
Vol 18 (1) ◽  
pp. 28-32 ◽  
Author(s):  
V.N. Bindal ◽  
V.R. Singh ◽  
Gurmukh Singh

Author(s):  
M. D. Vaudin ◽  
J. P. Cline

The study of preferred crystallographic orientation (texture) in ceramics is assuming greater importance as their anisotropic crystal properties are being used to advantage in an increasing number of applications. The quantification of texture by a reliable and rapid method is required. Analysis of backscattered electron Kikuchi patterns (BEKPs) can be used to provide the crystallographic orientation of as many grains as time and resources allow. The technique is relatively slow, particularly for noncubic materials, but the data are more accurate than any comparable technique when a sufficient number of grains are analyzed. Thus, BEKP is well-suited as a verification method for data obtained in faster ways, such as x-ray or neutron diffraction. We have compared texture data obtained using BEKP, x-ray diffraction and neutron diffraction. Alumina specimens displaying differing levels of axisymmetric (0001) texture normal to the specimen surface were investigated.BEKP patterns were obtained from about a hundred grains selected at random in each specimen.


1993 ◽  
Vol 140 (6) ◽  
pp. 485 ◽  
Author(s):  
J.-C. Montaño ◽  
A. López ◽  
M. Castilla ◽  
J. Gutierrez

Phlebologie ◽  
2002 ◽  
Vol 31 (04) ◽  
pp. 85-90 ◽  
Author(s):  
H.-M. Häfner ◽  
H. Bablich ◽  
G. Rassner ◽  
M. Jünger ◽  
A. Steins

Zusammenfassung Ziel: Überprüfung der Korrelation der photooptischen Venenfunktionstests Lichtreflexionsrheographie (LRR), digitale Photoplethysmographie (DPPG) und der Quecksilberdehnungsstreifen- Plethysmographie (Hg-strain gauge) mit der Phlebodynamometrie (PDM). Methode: Die simultane Messung von LRR, DPPG, Hg-strain gauge und PDM wurde an 34 Patienten mit chronischer venöser Insuffizienz in den klinischen Stadien I bis III nach Widmer an insgesamt 39 Unterschenkeln vorgenommen. Die Messungen erfolgten während Dorsalextension des Fußes in sitzender und während Plantarflexion des Fußes in stehender Position. Als Parameter für die Ermittlung des Korrelationskoeffizienten wurden die Wiederauffüllzeiten t0 und t1/2 sowie die venöse Abpumpleistung ermittelt. Ergebnisse: Unabhängig von Körperposition und Anlage von Tourniquets erreichten die Korrelationen für alle Messverfahren und Parameter Werte zwischen r = 0,76 (t0 LRR) und r = 0,05 (Abpumpleistung DPPG automatische Auswertung). Eine gute Korrelation von t0 wurde in stehender Körperposition unabhängig von der Anlage der Tourniquets beim Hg-strain gauge (r = 0,49) und LRR (r = 0,51) erreicht. Diese Korrelation verbesserte sich in sitzender Körperposition. Die schlechteste Korrelation wurde bei der DPPG ermittelt (r = 0,25 in stehender, r = 0,51 in sitzender Position). Eine Verbesserung der Korrelation wurde beim DPPG durch die manuelle Auswertung der Kurven erreicht. Schlussfolgerung: Sowohl die Wahl des Untersuchungsverfahrens wie auch das gewählte Belastungsprogramm können erhebliche Auswirkungen auf die Korrelation mit der PDM haben. Unsere Ergebnisse zeigen, dass bei der Bewertung der Wiederauffüllzeiten t0 und t1/2 der Hg-strain gauge und die LRR die höchste Korrelation bei Dorsalextension in sitzender Körperposition mit der PDM aufweisen.


1982 ◽  
Vol 47 (02) ◽  
pp. 141-144 ◽  
Author(s):  
H Bounameaux ◽  
B Krähenbühl ◽  
S Vukanovic

SummaryDoppler ultrasound flow examination, strain gauge plethysmography and contrast venography were performed in 160 lower limbs of 80 in-patients. Deep vein thrombosis (DVT) was suspected in 87 limbs. Using measurement of venous stop-flow pressure, the Doppler method had an overall sensitivity of 83%. By combined use of Doppler and Plethysmography, sensitivity was increased to 96%. Specificity was 62% and 51%, respectively. With a positive and a negative predictive value of 80% and 73%, respectively, the combination of both non-invasive methods cannot reliably replace venography in the diagnosis of DTV, although all (40/40) thromboses proximal to or involving the popliteal segment were detected by either Doppler and Plethysmography or both.After exclusion of 14 patients (18%) suffering from conditions known to alter the results of these non-invasive methods, the positive predictive value of abnormal findings in both Doppler and Plethysmography was increased to 94% for suspected limbs, whilst negative predictive value of both negative Doppler and Plethysmography was 90%, allowing the avoidance of venography in these patients.


2019 ◽  
Vol 139 (4) ◽  
pp. 63-68
Author(s):  
Hiroshi Nakano ◽  
Masahiro Matsumoto ◽  
Yasuo Onose ◽  
Kazuhiro Ohta

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