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bright-field illumination

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Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006684
EISBN: 978-1-62708-213-6
... what can be achieved using the light microscope, as shown in this article. For the study of the microstructure of metals and alloys, light microscopy is employed in the reflected-light mode using either bright-field illumination, dark-field illumination, polarized light illumination, oblique...
Series: ASM Handbook
Volume: 12
Publisher: ASM International
Published: 01 January 1987
DOI: 10.31399/asm.hb.v12.a0001835
EISBN: 978-1-62708-181-8
... and depth of field are both enhanced with small final apertures. As expected, the apertures must be centered in the optical axis and must be regularly replaced because of the accumulation of contaminants. Maintenance of the illumination/imaging system requires replacement of filaments (average...
Series: ASM Handbook
Volume: 5
Publisher: ASM International
Published: 01 January 1994
DOI: 10.31399/asm.hb.v05.a0001237
EISBN: 978-1-62708-170-2
... offers a number of forms of illumination for revealing surface detail: Bright-field illumination is the most widely used. The incident light is reflected back through the objective, producing a bright background with dark features. Dark-field illumination is particularly useful for analyzing...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006765
EISBN: 978-1-62708-295-2
... differential interference contrast illumination, and (b) a direct micrograph, using bright-field illumination, of a heavily nitrided AISI 4150 chuck jaw etched with nital. Note that the replica does not reveal the crack and is a mirror image of the bright-field micrograph. Replicas for metallographic...
Series: ASM Handbook
Volume: 12
Publisher: ASM International
Published: 01 January 1987
DOI: 10.31399/asm.hb.v12.a0001834
EISBN: 978-1-62708-181-8
... prevent the innovative metallographer from pursuing fractography beyond macroscopic techniques. Direct optical examination of the fracture and examination of the fracture profile with cross sections will often provide the required information. Zapffe's work involved bright-field illumination, which is...
Series: ASM Handbook
Volume: 12
Publisher: ASM International
Published: 01 January 1987
DOI: 10.31399/asm.hb.v12.a0001833
EISBN: 978-1-62708-181-8
... the depth of field of the recording lens. The optical axis is normal to the sheet of light formed by light sources that image a thin slit source of light on the object. The convergence and divergence of the illuminating beams limit the object width that will fall within the depth of field of the lens...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006763
EISBN: 978-1-62708-295-2
... photographic principles and techniques as applied to failure analysis, both in the field and in the laboratory. The discussion covers the processes involved in field and laboratory photographic documentations, provides a description of professional digital cameras, and gives information on photographic...
Series: ASM Handbook
Volume: 2
Publisher: ASM International
Published: 01 January 1990
DOI: 10.31399/asm.hb.v02.9781627081627
EISBN: 978-1-62708-162-7
Series: ASM Desk Editions
Publisher: ASM International
Published: 01 December 1998
DOI: 10.31399/asm.hb.mhde2.a0003244
EISBN: 978-1-62708-199-3
... occurring during abrasion. Grinding and polishing always produce a series of scratch grooves on the surface of the specimen; these scratches may be difficult to detect by light microscopy, particularly with bright-field illumination. Moreover, a plastically deformed, damaged layer is also introduced; the...
Series: ASM Handbook
Volume: 14A
Publisher: ASM International
Published: 01 January 2005
DOI: 10.31399/asm.hb.v14a.a0004018
EISBN: 978-1-62708-185-6
.... 31 Extremely fine twin bands in polished and plastically deformed titanium. (a) Groups of twin bands photographed with polarized light. Original magnification 200×. (b) Twin band and surrounding matrix in deformed titanium shown in (a). Thin-foil electron micrograph; bright-field illumination...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006681
EISBN: 978-1-62708-213-6
... parallel stationary beam is illuminated on a specimen. This mode is useful for conventional TEM imaging, such as bright-field (BF) and dark-field (DF) TEM imaging, high-resolution TEM imaging, and conventional electron diffraction analysis, including selected-area electron diffraction. This mode is also...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006447
EISBN: 978-1-62708-190-0
... through a flexible light guide cable for maximizing transmission of uniform, quality illumination of the inspected area. The need to access non-line-of-sight areas and the evolution of fiber optics bundles led to the field of RVI using fiberscopes ( Fig. 16 ). The core concepts are the same as those for...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006439
EISBN: 978-1-62708-190-0
... dark field. (d) Frontlighting, direct bright field. (e) Frontlighting, polarized. (f) Structured light. Source: Ref 1 Once the workpiece or scene has been properly arranged and illuminated, an image sensor is used to generate the electronic signal representing the image. The image sensor...
Series: ASM Handbook
Volume: 23
Publisher: ASM International
Published: 01 June 2012
DOI: 10.31399/asm.hb.v23.a0005685
EISBN: 978-1-62708-198-6
..., scratches, and particles. Thus, subtle features that may be completely invisible in bright-field microscopy are readily observed with this method. Microscope magnification is calibrated against reference standards. Lateral feature dimensions can be measured to an accuracy better than 0.5 μm. Computer...
Series: ASM Handbook
Volume: 5A
Publisher: ASM International
Published: 01 August 2013
DOI: 10.31399/asm.hb.v05a.9781627081719
EISBN: 978-1-62708-171-9
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006466
EISBN: 978-1-62708-190-0
... positioning of the sample to known areas. The SLAM acoustic images also provide useful and easily interpreted quantitative data about the sample. For example, the brightness of the image corresponds to the acoustic transmission level. By removing the sample and restoring the image brightness level with a...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006468
EISBN: 978-1-62708-190-0
... Abstract Magnetic-particle inspection is a method of locating surface and subsurface discontinuities in ferromagnetic materials. This article discusses the applications and advantages and limitations of magnetic-particle inspection. It describes magnetic fields in terms of magnetized ring...
Series: ASM Handbook
Volume: 10
Publisher: ASM International
Published: 15 December 2019
DOI: 10.31399/asm.hb.v10.a0006668
EISBN: 978-1-62708-213-6
... , Eq 5 shows that smaller beam diameters are achieved by increasing β and decreasing the spherical aberration coefficient, C s . Maximum resolution requires a minimum d s , which requires maximum values of β, ε, and t f and minimum C s values. Field-emission sources have higher brightness...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006764
EISBN: 978-1-62708-295-2
... discontinuities in the translucent material and any variations in material thickness. Magnetic-particle inspection (MPI) uses magnetic fields to locate surface and subsurface discontinuities in ferromagnetic materials. When the material or part to be tested is magnetized, discontinuities that generally...
Series: ASM Handbook
Volume: 17
Publisher: ASM International
Published: 01 August 2018
DOI: 10.31399/asm.hb.v17.a0006443
EISBN: 978-1-62708-190-0
... development is associated with the fundamental nature of the measurement. In essence, the measurement response is a complex function of the probe fields and their interaction with the flaw, and it is difficult to isolate these two contributions. Therefore, one cannot develop simple models in which various...