scholarly journals Model of a Light Extinction Sensor for Assessing Wear Particle Distribution in a Lubricated Oil System

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4091
Author(s):  
Kevin Krogsøe ◽  
Morten Henneberg ◽  
René Eriksen
Keyword(s):  
Particle Concentration ◽  
Particle Distribution ◽  
Optical Design ◽  
Signal Amplitude ◽  
Wear Particle ◽  
Light Extinction ◽  
Contamination Level ◽  
Special Focus ◽  
Particle Contamination ◽  
Measurement Principle

Light extinction based optical wear particle counters (OPCs) have been widely used in the industry for oil condition monitoring for several years, and while experiments have tested the benefits and drawbacks of the measurement principle, limited research has been conducted regarding a theoretical approach to evaluate opportunities and limitations of the measurement scheme. In this paper, we present a method for theoretically modelling the output of an OPC based on the light extinction principle in the regime of geometrical optics, with a special focus on the influence of sensor optical design, particle concentration and measurement noise. Moreover, we show that, if only signal amplitude is considered, an algorithm for evaluating sensor output can cause an erroneous assessment of particle contamination level.

Measurement of diesel particle concentration by the radiometric measurement principle

1990 ◽  
Vol 21 ◽  
pp. S587-S590
Author(s):  
H. Dreiheller ◽  
D. Rensing ◽  
K. Stauber ◽  
N. Trost ◽  
H. Wendt
Keyword(s):  
Particle Concentration ◽  
Radiometric Measurement ◽  
Measurement Principle

The SCATMES Device for Measurement of Concentrated Solar Radiation

1999 ◽  
Vol 121 (2) ◽  
pp. 116-120 ◽  
Author(s):  
A. Neumann ◽  
A. Schmitz
Keyword(s):  
Solar Radiation ◽  
Measurement System ◽  
Flux Distribution ◽  
Optical Design ◽  
Video Camera ◽  
Solar Furnace ◽  
Camera Systems ◽  
Measurement Principle ◽  
Concentrated Solar Radiation ◽  
Compact Geometry

Video camera systems monitoring a diffuse reflecting target for measuring the flux distribution of concentrated solar radiation are quite common. This technique cannot be used if parts of the experimental setup screen the surface of the target. The development of a new measurement system with a compact geometry and a new optical design is described. With this system it is possible to measure the flux distribution behind parts of an experiment and at any position of the plane of measurement, without any alteration of the setup. The sources of error, especially those of the target and the camera, are described and discussed, and finally a comparison to the existing FATMES-System, which has been performed at the solar furnace of the DLR in Cologne, is presented. Due to its measurement principle the new system is called ’Scanning Camera and Target Measurement System‘ (acronym: SCATMES).

Nuclear Magnetiic Resonance Imaging (NMRI) of Flow-Induced Microstructure of Concentratied Suspensions

1992 ◽  
Vol 289 ◽  
Author(s):  
A. W. Chow ◽  
S. W. Sinton ◽  
J. H. Iwamiya
Keyword(s):  
Particle Concentration ◽  
Particle Distribution ◽  
Leading Edge ◽  
Particle Migration ◽  
Fall Velocity ◽  
Resonance Flow ◽  
Liquid Suspensions ◽  
Induced Changes ◽  
Solid Liquid ◽  
Neutrally Buoyant

AbstractThe application of nuclear magnetic resonance flow imaging (NMRI) to the study of Couette and falling-ball viscometry of solid/liquid suspensions is described. The suspension consisted of non-Brownian, monodisperse, neutrally-buoyant spheres of 50 vol%. NMRI data demonstrated flow-induced changes in the particle distribution in the suspension that strongly influence the accuracy in viscosity measurements using these flow geometries. In Couette flow, direct correlation between stress measurements and particle concentrations at various locations in the flow cell as a function of shear strain can be made. Our data directly confitrm the shearinduced particle migration theory proposed by Leighton and Acrivos.[1] In the falling-ball experiments, increased particle concentration at the leading edge and decreased concentration at the trailing edge of the ball was observed when the falling ball is big compared to the cylinder containing the suspension. This change in particle distribution can be directly related to the changes in fall velocity of the ball as a function of position in the cylinder.

scholarly journals High spectral resolution lidar based on quad mach zehnder interferometer for aerosols and wind measurements on board space missions

2018 ◽  
Vol 176 ◽  
pp. 02017
Author(s):  
Jean-François Mariscal ◽  
Didier Bruneau ◽  
Jacques Pelon ◽  
Mathilde Van Haecke ◽  
Frédéric Blouzon ◽  
...  
Keyword(s):  
Optical Design ◽  
High Spectral Resolution ◽  
Space Applications ◽  
Readiness Level ◽  
Wind Measurements ◽  
Measurement Principle ◽  
Key Features ◽  
Particle Backscattering ◽  
Technical Readiness ◽  
High Spectral Resolution Lidar

We present the measurement principle and the optical design of a Quad Mach Zehnder (QMZ) interferometer as HSRL technique, allowing simultaneous measurements of particle backscattering and wind velocity. Key features of this concept is to operate with a multimodal laser and do not require any frequency stabilization. These features are relevant especially for space applications for which high technical readiness level is required.

scholarly journals Particle Size and Pre-Treatment Effects on Polystyrene Microplastic Settlement in Water: Implications for Environmental Behavior and Ecotoxicological Tests

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3436
Author(s):  
Lars Eitzen ◽  
Aki Sebastian Ruhl ◽  
Martin Jekel
Keyword(s):  
Size Distribution ◽  
Ultrasonic Treatment ◽  
Particle Concentration ◽  
Light Extinction ◽  
High Reproducibility ◽  
Mechanical Dispersion ◽  
Toxicological Studies ◽  
Calculated Volume ◽  
Pre Treatment ◽  
Number Of Particles

Microplastic (MP) particle dispersions used in many recent publications covering adsorption or toxicological studies are not characterized very well. The size distribution of polydisperse dispersions is highly dependent on the agglomeration processes and influences experimental outcomes. Therefore, pre-treatment is a prerequisite for reproducibility. In this study, manual/automated shaking and ultrasonic treatment as different mechanical dispersion techniques were applied for the dispersion of cryomilled polystyrene (PS). Particle numbers and size distribution of dispersions were analyzed by a light extinction particle counter and the dispersion efficiency (ED) as the ratio between calculated volume and theoretical volume of suspended particles was used to compare techniques. PS dispersions (20 mg/L) treated for 90 min in an ultrasonic bath (120 W, 35 kHz) were evenly dispersed with a particle concentration of 140,000 particles/mL and a high reproducibility (rel. SD = 2.1%, n = 6). Automated horizontal shaking for 754 h (250 rpm) reached similar particle numbers (122,000/mL) but with a lower reproducibility (rel. SD = 9.1%, n = 6). Manual shaking by hand dispersed the lowest number of particles (55,000/mL) and was therefore found to be unsuitable to counteract homo-agglomeration. ED was calculated as 127%, 104% and 69% for ultrasonic treatment, horizontal shaking and manual shaking, respectively, showing an overestimation of volume assuming spherical shaped particles.

Debris Detection in Hydraulic Oil Using a Microfluidic Inductive Pulse Device

2012 ◽  
Author(s):  
Hongpeng Zhang ◽  
Wen Huang ◽  
Junwei Jin ◽  
Li Guo ◽  
Dongqing Li
Keyword(s):  
Wear Debris ◽  
Wear Particle ◽  
Metal Particles ◽  
Iron Particles ◽  
Essential Information ◽  
Copper Particles ◽  
Hydraulic Oil ◽  
Metal Wear ◽  
Particle Contamination ◽  
The Relationship

Metal wear debris is an important component of oil particle contamination and is also an essential information carrier in hydraulic oil. Based on inductive Coulter counting principle, a microfluidic device to detect wear debris in oil is presented. The proposed device has the advantage that in theory the distance between wear particle in oil and an embedded coil is 0, which can greatly improve the sensitivity of detection. The relationship between coil parameters and inductive change of a coil is analyzed through the related experimental statistics. The result indicates it can distinguish effectively ferrous and nonferrous metal particles in oil, and the size of 19 μm iron particles and 40 μm copper particles can be detected.

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