High-speed noncontact fiber-diameter measurement using forward light scattering

1977 ◽  
Vol 16 (9) ◽  
pp. 2395 ◽  
Author(s):  
D. H. Smithgall ◽  
L. S. Watkins ◽  
R. E. Frazee
Keyword(s):  
Light Scattering ◽  
High Speed ◽  
Fiber Diameter ◽  
Diameter Measurement

scholarly journals Optical-Trapping Laser Techniques for Characterizing Airborne Aerosol Particles and Its Application in Chemical Aerosol Study

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 466
Author(s):  
Aimable Kalume ◽  
Chuji Wang ◽  
Yongle Pan
Keyword(s):  
Light Scattering ◽  
High Speed ◽  
Optical Trapping ◽  
Aerosol Particles ◽  
Particle Interaction ◽  
Raman Laser ◽  
General Description ◽  
Sample Collection ◽  
Laser Technologies ◽  
Laser Induced Breakdown

We present a broad assessment on the studies of optically-trapped single airborne aerosol particles, particularly chemical aerosol particles, using laser technologies. To date, extensive works have been conducted on ensembles of aerosols as well as on their analogous bulk samples, and a decent general description of airborne particles has been drawn and accepted. However, substantial discrepancies between observed and expected aerosols behavior have been reported. To fill this gap, single-particle investigation has proved to be a unique intersection leading to a clear representation of microproperties and size-dependent comportment affecting the overall aerosol behavior, under various environmental conditions. In order to achieve this objective, optical-trapping technologies allow holding and manipulating a single aerosol particle, while offering significant advantages such as contactless handling, free from sample collection and preparation, prevention of contamination, versatility to any type of aerosol, and flexibility to accommodation of various analytical systems. We review spectroscopic methods that are based on the light-particle interaction, including elastic light scattering, light absorption (cavity ring-down and photoacoustic spectroscopies), inelastic light scattering and emission (Raman, laser-induced breakdown, and laser-induced fluorescence spectroscopies), and digital holography. Laser technologies offer several benefits such as high speed, high selectivity, high accuracy, and the ability to perform in real-time, in situ. This review, in particular, discusses each method, highlights the advantages and limitations, early breakthroughs, and recent progresses that have contributed to a better understanding of single particles and particle ensembles in general.

Fiber diameter measurement of bulk man-made vitreous fiber

1993 ◽  
Vol 280 (2) ◽  
pp. 289-298 ◽  
Author(s):  
A.R. Koenig ◽  
R.D. Hamilton ◽  
T.E. Laskowski ◽  
J.R. Olson ◽  
J.F. Gordon ◽  
...  
Keyword(s):  
Fiber Diameter ◽  
Diameter Measurement

High Precision Machine Vision System for Outer Diameter Inspection Bearing

2013 ◽  
Vol 552 ◽  
pp. 313-318
Author(s):  
Yuan Gao ◽  
Guo Yu Zhang
Keyword(s):  
Machine Vision ◽  
Optical System ◽  
High Speed ◽  
Measurement Accuracy ◽  
Polynomial Interpolation ◽  
Vision System ◽  
Outer Diameter ◽  
Machine Vision System ◽  
Diameter Measurement ◽  
Ccd Image

A machine vision system for bearing outer diameter inspection has been developed in this paper. The infinite objective of optical system is applied to diameter measurement system. The paper provides a method for measuring the size of objects based on polynomial interpolation. The technology of CCD image stagger is applied in the paper. The method can avoid space between pixels astriction theoretically, so higher measurement accuracy is gained. The experiment results show that the system has many advantages such as non- touch , high speed and higher precision.

scholarly journals Experimental Study of the Meltblowing Process

1999 ◽  
Vol os-8 (1) ◽  
pp. 1558925099OS-80 ◽  
Author(s):  
Hong Yin ◽  
Zanyao Yan ◽  
Randall R. Bresee
Keyword(s):  
High Speed ◽  
Fiber Diameter ◽  
Imaging Techniques ◽  
Infrared Camera ◽  
Short Exposure ◽  
Short Exposure Time ◽  
Strobe Light ◽  
Single Hole ◽  
Fiber Motion ◽  
Conventional Film

High-speed digital imaging techniques and web measurements were used to investigate the meltblowing (MB) process. We evaluated fiber diameter, fiber orientation, fiber entanglement, fiber velocity and fiber acceleration between the die and collector. Three processing variables were studied: primary air pressure, die-to-collector distance and collector surface speed. Although results of this investigation are somewhat preliminary, they provide fundamental information about the MB process and increase our understanding of it. Introduction Meltblowing (MB) is a fast, chaotic and complicated process. These features make it difficult to study the MB process theoretically as well as experimentally and most researchers have simply studied the effects of resin and process variables on web structure or web properties. Some researchers, however, have reported on-line measurements during MB [1–9]. Bansal and Shambaugh measured fiber temperature during single-hole MB using an infrared camera [1]. Wu and Shambaugh measured fiber velocity using laser Doppler velocimetry during single-hole MB [2]. Shambaugh and others reported experimental measurements of fiber motion and fiber diameter using a single-hole die [1–7]. Multiple-exposed photographs using conventional film were produced with a strobe light in a dark room to study fiber motion and single-exposed photographs were used to estimate fiber diameter. The exposure duration of the strobe light (50 μs), however, was not short enough to eliminate image blur and obtain sharp images so the primary air velocity used during MB was low (17–55 m/s). Milligan and Utsman used a similar film-based photographic technique to investigate MB using a 30-hole die [8]. Bresee and Yan used a video imaging technique to investigate the dynamics of web formation at the collector of a 600-hole MB line [9]. Measurements of the dynamics between the die and collector of a high-speed commercial-like MB process would be expected to be especially desirable for understanding MB. To directly observe dynamic motions during this fast process, it is necessary to use a short exposure time to freeze motion in each image and a high framing rate to resolve fast fiber motions. We used a high-speed digital camera from Vision Research Inc. to acquire images as rapidly as 1,000 frames/s. The camera produced image frames with a spatial resolution as great as 512×512 pixels and 8-bit gray level resolution (256 gray levels). Electronic shuttering of the camera provided exposure times as short as 50 μs/frame. To obtain exposure times shorter than 50 μs or to obtain multiple-exposed images, a high-speed pulsed laser from Oxford Lasers, Inc. was used for illumination. The laser produced 100 watt peak power at 805 nm and pulse durations as short as 1 μs were synchronized with the camera.

Sign in / Sign up

Export Citation Format

Share Document