Signal Analysis of Scratch-Detection on Magnetic Disc by Using Light Reflection Approach

2015 ◽  
Vol 781 ◽  
pp. 203-206 ◽  
Author(s):  
Achinee Polsawat ◽  
Nattawoot Suwannata ◽  
Apirat Siritaratiwat ◽  
Anan Kruesubthaworn
Keyword(s):  
Laser Beam ◽  
Signal Analysis ◽  
Quality Inspection ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Recording Head ◽  
Process Machinery ◽  
Magnetic Disc ◽  
Non Destructive ◽  
Scratch Detection

In hard disk manufacturing, a process of quality inspection of magnetic disc is crucially focused on finding traces of scratch that occur on the surface by various sources such as production process, machinery, tribology or recording head. It may affect the efficiency of magnetic disc’s read/write ability. Many approaches have been proposed to detect the scratch by either destructive or non-destructive testing. In this study, it shows an analysis of signals from the detected scratches on the magnetic disc by reflection light method, using a CD pick-up head. It works by producing an incidental laser beam to the surface and then detecting it by a photodiode detector. The results showed that when the laser beam is incident onto the magnetic disc with/ without scratch, reflecting lights to the photodiode are different and the signal changes according to the intensity of the incidental/reflecting lights.

Review on the Development of Non-Destructive Testing Based on Laser Ultrasonic Technique

2014 ◽  
Author(s):  
Yuanfeng He ◽  
Wenwu Zhang
Keyword(s):  
Quality Control ◽  
Optical Method ◽  
Vibration Signal ◽  
Quality Inspection ◽  
Ultrasonic Technique ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Laser Ultrasonic ◽  
Ultrasonic Technology ◽  
Non Destructive

Development of industry demands better performance of equipments and devices than ever. The property of material used to produce the equipments is the precondition to ensure the quality. As equipments are usually required to be integral during the quality inspection, non-destructive testing (NDT) plays an increasingly import role in modern industry quality control. Different NDT methods are introduced and analyzed. The mechanism of ultrasonic exciting is described. After the ultrasonic is excited, the vibration signal can be detected by transducer or optical method which are then illustrated. In the section of development of laser ultrasonic technology, contributions made by various researchers in theoretic development, experiment, simulation and application are introduced and the corresponding content of the researches as well. The conclusion and the outlook of laser ultrasonic technique is made at the last.

Fatigue Crack Propagation Monitoring by Acoustic Emission Signal Analysis

2011 ◽  
Vol 465 ◽  
pp. 370-373 ◽  
Author(s):  
Paola Antonaci ◽  
Pietro G. Bocca ◽  
Davide Masera
Keyword(s):  
Acoustic Emission ◽  
Signal Analysis ◽  
Mechanical Response ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Testing Laboratory ◽  
Cyclic Action ◽  
Emission Signal ◽  
Non Destructive

The aim of this work is to analyse the mechanical response of the masonry specimens under long-term action by means of cyclic tests. To this end laboratory tests were carried out at the Non-Destructive Testing Laboratory of the Politecnico di Torino. The Acoustic Emission technique was employed to assess the damage evolution, and the mechanical properties decay in order to evaluate the extent and the evolution of micro and macro-cracking due to cyclic action until structural collapse in masonry blocks and mortar layers.

Non-destructive testing of full-length bonded rock bolts based on HHT signal analysis

2018 ◽  
Vol 151 ◽  
pp. 47-65 ◽  
Author(s):  
Z.M. Shi ◽  
L. Liu ◽  
M. Peng ◽  
C.C. Liu ◽  
F.J. Tao ◽  
...  
Keyword(s):  
Signal Analysis ◽  
Full Length ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Rock Bolts ◽  
Non Destructive

Application of computerised radiography in lieu of film radiography to streamline on-site pipe weld quality inspection process

2019 ◽  
Vol 59 (2) ◽  
pp. 785
Author(s):  
Mangala Fernando ◽  
Hamid Fard
Keyword(s):  
Environmental Issues ◽  
Imaging Plate ◽  
Quality Inspection ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
X Ray ◽  
Conventional Film ◽  
Inspection Process ◽  
Space Requirements ◽  
Non Destructive

Conventional film radiography has long been the dominant method of non-destructive testing in the Australian pipeline industry. Although proven, the process has disadvantages, including environmental issues with chemical processing and film disposal, significant archival space requirements, film deterioration, and difficulty in traceability and safe sharing with others. In contrast, computerised radiography (CR), using a phosphorus-laden reusable imaging plate and X-ray radiation to generate a latent digitally scannable image, is a clean, compact and efficient process. Although CR has been used on other applications, such as profile radiography for more than a decade, the process has not been considered advanced enough for weld testing until now. After a comprehensive qualification/validation process, CR was successfully used on 481 km of the 622-km-long Northern Gas Pipeline (NGP) Project by McConnell Dowell in the Northern Territory. Proven on approximately 26000 welds, this thinking has changed for good.

Non destructive testing of works of art by terahertz analysis

2013 ◽  
Vol 64 (2) ◽  
pp. 21001 ◽  
Author(s):  
Jean-Luc Bodnar ◽  
Jean-Jacques Metayer ◽  
Kamel Mouhoubi ◽  
Vincent Detalle
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Works Of Art ◽  
Non Destructive

Modeling of a sensitive element on a planar mushroom-shaped metamaterial for non-destructive testing and searching for inhomogeneities in technological media

2020 ◽  
pp. 54-59
Author(s):  
A. A. Yelizarov ◽  
A. A. Skuridin ◽  
E. A. Zakirova
Keyword(s):  
Sensitive Element ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Resonant Frequency Shift ◽  
Maltese Cross ◽  
Informative Parameters ◽  
Non Destructive ◽  
Cross Type ◽  
Electrodynamic Structure ◽  
Electrophysical Parameters

A computer model and the results of a numerical experiment for a sensitive element on a planar mushroom-shaped metamaterial with cells of the “Maltese cross” type are presented. The proposed electrodynamic structure is shown to be applicable for nondestructive testing of geometric and electrophysical parameters of technological media, as well as searching for inhomogeneities in them. Resonant frequency shift and change of the attenuation coefficient value of the structure serve as informative parameters.

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