Design of On-Line Measurement System of Film Thickness Based on Infrared Technology

2017 ◽  
Vol 865 ◽  
pp. 619-623
Author(s):  
Ping He ◽  
Ji Kai Yu ◽  
Long Hua Hong

The thickness of the plastic film is an important physical index to the production of plastic. The measurement reslut relates directly to the companies’ economic benefit. This paper mainly introduces the digital signal processing in the detection system of film thickness. Through a perfect processing, the system can improve its SNR and finally get a high precision. Firstly, the principle and scheme was presented. After that, this paper mainly introduces the hardware implementation of the system. It includes analog filter circuit, AD sampling and digital filter. With the experimental verification, the system realizes the measurement of the film thickness on-line which can get the precision of micrometer. At present, the equipment has aready put into use by some companies.

2014 ◽  
Vol 893 ◽  
pp. 751-754
Author(s):  
Peng Wang ◽  
Song Nan Wang ◽  
Ji Xin Chen ◽  
Ming Xin Ren ◽  
Hai Bo Huang ◽  
...  

sensor used in DC ground fault detection system according to measurement method can be divided into low frequency AC signal detecting and DC signal detecting of leakage current . It greatly affect the accuracy of the earth fault signal because of the existence of capacitance in the detecting of low frequency AC signal and it doesnt have online measurement DC current sensor in the market when we want to measure load leakage current. Caliper DC ammeter cant meet the requirements in DC system ground fault diction in terms of resolution, accuracy, range, on-line installation and on-line measurement.


2010 ◽  
Vol 43 ◽  
pp. 68-71
Author(s):  
Li Sun ◽  
Shi Qing Zhang ◽  
Jian Rong Cai ◽  
Hao Lin ◽  
Gen Gen Fang

An on-line system which based on acoustic resonance employed digital signal processer (DSP) as its core device for eggshell crack detection. The system consists of the IR trigger for detecting the egg’s coming, the motor drive for driving the DC motor, the signal conditioning circuit for signal amplification and filter and DSP for control and signal processing. Based on the analysis of response signal of eggshell which excited with a light mechanical, four featured descriptors were exacted for discriminating intact and cracked eggs. By using the on-line system for detection of cracked eggs, the identification rates of intact eggs and cracked eggs were 93.75% and 96.25%, respectively. This system can detect 5 eggs within one second, it completely meet the needs of on-line detection.


1998 ◽  
Vol 34 (10) ◽  
pp. 1289-1295
Author(s):  
Katsue KOASHI ◽  
Shuusaku SHIGETA ◽  
Hiroshi YOKOTA ◽  
Masaaki KIMURA

Author(s):  
John F. Mansfield ◽  
Douglas C. Crawford

A method has been developed that allows on-line measurement of the thickness of crystalline materials in the analytical electron microscope. Two-beam convergent beam electron diffraction (CBED) patterns are digitized from a JEOL 2000FX electron microscope into an Apple Macintosh II microcomputer via a Gatan #673 CCD Video Camera and an Imaging Systems Technology Video 1000 frame-capture board. It is necessary to know the lattice parameters of the sample since measurements are made of the spacing of the diffraction discs in order to calibrate the pattern. The sample thickness is calculated from measurements of the spacings of the fringes that are seen in the diffraction discs. This technique was pioneered by Kelly et al, who used the two-beam dynamic theory of MacGillavry relate the deviation parameter (Si) of the ith fringe from the exact Bragg condition to the specimen thickness (t) with the equation:Where ξg, is the extinction distance for that reflection and ni is an integer.


Author(s):  
Maoxu Qian ◽  
Mehmet Sarikaya ◽  
Edward A. Stern

It is difficult, in general, to perform quantitative EELS to determine, for example, relative or absolute compositions of elements with relatively high atomic numbers (using, e.g., K edge energies from 500 eV to 2000 eV), to study ELNES (energy loss near edge structure) signal using the white lines to determine oxidation states, and to analyze EXELFS (extended energy loss fine structure) to study short range ordering. In all these cases, it is essential to have high signal-to-noise (S/N) ratio (low systematical error) with high overall counts, and sufficient energy resolution (∽ 1 eV), requirements which are, in general, difficult to attain. The reason is mainly due to three important inherent limitations in spectrum acquisition with EELS in the TEM. These are (i) large intrinsic background in EELS spectra, (ii) channel-to-channel gain variation (CCGV) in the parallel detection system, and (iii) difficulties in obtaining statistically high total counts (∽106) per channel (CH). Except the high background in the EELS spectrum, the last two limitations may be circumvented, and the S/N ratio may be attained by the improvement in the on-line acquisition procedures. This short report addresses such procedures.


2013 ◽  
Vol 40 (12) ◽  
pp. 1945-1949
Author(s):  
Xue-Jin GAO ◽  
Guang-Sheng LIU ◽  
Li CHENG ◽  
Ling-Xiao GENG ◽  
Ji-Xing XUE ◽  
...  

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