High-Frequency Phonon Dynamics in LaF3 Using Monoenergetic Optical Detection Methods

1984 ◽  
pp. 115-117 ◽  
Author(s):  
R. S. Meltzer ◽  
J. E. Rives ◽  
D. J. Sox ◽  
C. S. Dixon
Keyword(s):  
High Frequency ◽  
Optical Detection ◽  
Detection Methods ◽  
Phonon Dynamics

Optical detection methods for laser guided unmanned devices

2018 ◽  
Vol 20 (5) ◽  
pp. 464-472 ◽  
Author(s):  
Vadim Stary ◽  
Vaclav Krivanek ◽  
Alexandr Stefek
Keyword(s):  
Optical Detection ◽  
Detection Methods

Partial Discharge Detection Using Acoustic and Optical Methods in High Voltage Power Equipments: A Review

2013 ◽  
Vol 845 ◽  
pp. 283-286 ◽  
Author(s):  
Malik Abdul Razzaq Al Saedi ◽  
Mohd Muhridza Yaacob
Keyword(s):  
Acoustic Emission ◽  
High Voltage ◽  
Power Transformer ◽  
Partial Discharge ◽  
Optical Detection ◽  
Detection Threshold ◽  
Optical Methods ◽  
Detection Methods ◽  
Detection Techniques ◽  
Advantages And Disadvantages

There is a high risk of insulation system dielectric instability when partial discharge (PD) occurs. Therefore, measurement and monitoring of PD is an important preventive tool to safeguard high-voltage equipment from wanton damage. PD can be detected using optical method to increase the detection threshold and to improve the performance of on-line measurement of PD in noise environment. The PD emitted energy as acoustic emission. We can use this emitted energy to detect PD signal. The best method to detect PD in power transformer is by using acoustic emission. Optical sensor has some advantages such as; high sensitivity, more accuracy small size. Furthermore, in on-site measurements and laboratory experiments, it isoptical methodthat gives very moderate signal attenuations. This paper reviews the available PD detection methods (involving high voltage equipment) such as; acoustic detection and optical detection. The advantages and disadvantages of each method have been explored and compared. The review suggests that optical detection techniques provide many advantages from the consideration of accuracy and suitability for the applications when compared to other techniques.

scholarly journals Review of Dissolved Oxygen Detection Technology: From Laboratory Analysis to Online Intelligent Detection

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3995 ◽  
Author(s):  
Yaoguang Wei ◽  
Yisha Jiao ◽  
Dong An ◽  
Daoliang Li ◽  
Wenshu Li ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Real Time ◽  
Optical Detection ◽  
Oxygen Sensors ◽  
Detection Methods ◽  
Future Research ◽  
Advantages And Disadvantages ◽  
Oxygen Detection ◽  
Detection Technology ◽  
Intelligent Technology

Dissolved oxygen is an important index to evaluate water quality, and its concentration is of great significance in industrial production, environmental monitoring, aquaculture, food production, and other fields. As its change is a continuous dynamic process, the dissolved oxygen concentration needs to be accurately measured in real time. In this paper, the principles, main applications, advantages, and disadvantages of iodometric titration, electrochemical detection, and optical detection, which are commonly used dissolved oxygen detection methods, are systematically analyzed and summarized. The detection mechanisms and materials of electrochemical and optical detection methods are examined and reviewed. Because external environmental factors readily cause interferences in dissolved oxygen detection, the traditional detection methods cannot adequately meet the accuracy, real-time, stability, and other measurement requirements; thus, it is urgent to use intelligent methods to make up for these deficiencies. This paper studies the application of intelligent technology in intelligent signal transfer processing, digital signal processing, and the real-time dynamic adaptive compensation and correction of dissolved oxygen sensors. The combined application of optical detection technology, new fluorescence-sensitive materials, and intelligent technology is the focus of future research on dissolved oxygen sensors.

A series of high-frequency EPR spectrometers with microwave and optical detection channels

2017 ◽  
Vol 43 (4) ◽  
pp. 393-395 ◽  
Author(s):  
R. A. Babunts ◽  
A. G. Badalyan ◽  
A. S. Gurin ◽  
B. R. Namozov ◽  
N. G. Romanov ◽  
...  
Keyword(s):  
High Frequency ◽  
Optical Detection

Current Detection Methods of Partial Discharge for Distribution Network Switchgear

2014 ◽  
Vol 521 ◽  
pp. 313-316
Author(s):  
Yu Sheng Quan ◽  
Lin Jie Fang ◽  
Yan Wu ◽  
Zi Jian Wang
Keyword(s):  
Electromagnetic Wave ◽  
High Frequency ◽  
Partial Discharge ◽  
Outer Wall ◽  
Detection Methods ◽  
Total Current ◽  
Current Signal ◽  
Current Detection ◽  
Ground Line ◽  
Frequency Current

There are many factors that can lead to partial discharge in the internal of switchgear. High-frequency current will be generated on the inner wall of switchgear when the electromagnetic wave generated by partial discharge reaches the enclosure of switchgear. In the same way, more complex current signal will be produced on the outer wall of the switchgear because of the electromagnetic radiation outside the enclosure. These two currents will flow to earth through the switchgear ground wire. We can determine whether the switchgear exist partial discharge and the severity of the partial discharge by comparing the current flowing through the outer wall and the total current flowing through the ground line.

scholarly journals Design and implementation of the subsystem subject to emission of multicomponent high-frequency signals to ensure its reliability

2019 ◽  
Vol 9 (5) ◽  
pp. 4204
Author(s):  
Milad Daneshvar ◽  
Naser Parhizgar ◽  
Homayoon Oraizi
Keyword(s):  
High Frequency ◽  
Detection Methods ◽  
System Behavior ◽  
Time Frequency ◽  
Telecommunication Systems ◽  
Multicomponent Signals ◽  
Extensive Range ◽  
Interference Signals ◽  
Analytic Signals ◽  
Phase Differences

Telecommunication systems, especially digital ones, are mostly known to be immune to noise given their extensive range of applications. This study aimed to investigate the methods and tools used for the analysis of multicomponent signals input to high-frequency digital subsystems, including the analysis of changes in its electrical behavior. This research mainly focuses on analyzing a high-frequency telecommunication subsystem, recording the results, investigating the system behavior against signals with different amplitudes and phases, detecting the received signals, and measuring the phase differences. The study extended the mono-component signals to multi-component signals and accurately extracted the statistical signal specifications using analytic signals in the time-frequency domain. To this end, a method was proposed based on the switch matrix to relate the different components and parameters, and also a mathematical model based on the state-space equations was employed to evaluate the nonlinear system modes. Given that the decoupling of measurement parameters is a problem to be tackled from multiple aspects, the costs and test durations were also taken into calculations in addition to considering all the detection methods for interference signals, reliability and time under test.

scholarly journals Photoacoustic-Based Gas Sensing: A Review

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2745 ◽  
Author(s):  
Stefan Palzer
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Optical Detection ◽  
Detection Limits ◽  
Review Article ◽  
Detection Methods ◽  
Attractive Alternative ◽  
Photoacoustic Effect ◽  
Miniaturized Devices

The use of the photoacoustic effect to gauge the concentration of gases is an attractive alternative in the realm of optical detection methods. Even though the effect has been applied for gas sensing for almost a century, its potential for ultra-sensitive and miniaturized devices is still not fully explored. This review article revisits two fundamentally different setups commonly used to build photoacoustic-based gas sensors and presents some distinguished results in terms of sensitivity, ultra-low detection limits, and miniaturization. The review contrasts the two setups in terms of the respective possibilities to tune the selectivity, sensitivity, and potential for miniaturization.

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