scholarly journals Application of Excimer Lamp in Quantitative Detection of SF6 Decomposition Component SO2

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8165
Author(s):  
Tunan Chen ◽  
Kang Li ◽  
Fengxiang Ma ◽  
Xinjie Qiu ◽  
Zongjia Qiu ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Detection System ◽  
Absorption Peak ◽  
Trace Gas ◽  
Quantitative Detection ◽  
Light Sources ◽  
Excimer Lamp ◽  
Sf6 Decomposition ◽  
Term Monitoring

Accurate quantitative detection for trace gas has long been the center of failure diagnosis for gas-insulated equipment. An absorption spectroscopy-based detection system was developed for trace SF6 decomposition SO2 detection in this paper. In order to reduce interference from other decomposition, ultraviolet spectrum of SO2 was selected for detection. Firstly, an excimer lamp was developed in this paper as the excitation of the absorption spectroscopy compared with regular light sources with electrodes, such as electrodeless lamps that are more suitable for long-term monitoring. Then, based on the developed excimer lamp, a detection system for trace SO2 was established. Next, a proper absorption peak was selected by calculating spectral derivative for further analysis. Experimental results indicated that good linearity existed between the absorbance and concentration of SO2 at the chosen absorption peak. Moreover, the detection limit of the proposed detection system could reach the level of 10−7. The results of this paper could serve as a guide for the application of excimer lamp in online monitoring for SF6-insulated equipment.

Cantilever enhanced based photoacoustic detection of SF6 decomposition component SO2 using UV LED

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tunan Chen ◽  
Fengxiang Ma ◽  
Yue Zhao ◽  
Zhenghai Liao ◽  
Zongjia Qiu ◽  
...  
Keyword(s):  
Detection Limit ◽  
Detection System ◽  
Light Sources ◽  
Photoacoustic Detection ◽  
Low Light ◽  
Power Requirement ◽  
Light Power ◽  
Content Type ◽  
Uv Led ◽  
Sf6 Decomposition

Purpose This paper aims to establish a photoacoustic detection system for SO2 using UV-LED and testify its feasibility for sensitive measurement. The work in this paper can avoid potential crossover interference in infrared (IR) range and also balance the capability and cost of feasible excitation for photoacoustic detection system. Design/methodology/approach In this experimental work, a cantilever-enhanced–based photoacoustic SO2 detection system using an ultraviolet (UV) LED light source with a light power of 4 mW as the excitation was established. Findings A feasible photoacoustic detection system for SO2 using UV-LED was established. Experimental results demonstrate that the detection limit of the system can reach the level of 0.667 ppm, which can serve as a reference for the application of PAS in insulation fault diagnosis. Originality/value This work investigated the potential of using ultraviolet photoacoustic spectroscopy to detect trace SO2, which provided an ideal replacement of infrared-laser-based detection system. In this paper, a photoacoustic detection system using LED with a low light power was established. Low light power requirement can expand the options of light sources accordingly. In this paper, the absorption characteristics of SO2 in the presented detection system and ultraviolet range were studied. And the detection limit of the presented system was given. Both of which can provide reference to SO2 detection in ambient SF6.

Ultraviolet Spectral Analysis and Quantitative Detection of Heptafluoroisobutyronitrile (C4F7N) in a C4F7N–Carbon Dioxide (CO2) Gas Mixture

2019 ◽  
Vol 73 (8) ◽  
pp. 917-926 ◽  
Author(s):  
Yin Zhang ◽  
Xiaoxing Zhang ◽  
Chang Liu ◽  
Yi Li ◽  
Zhaolun Cui ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Absorption Spectroscopy ◽  
Density Functional ◽  
Sulfur Hexafluoride ◽  
Detection System ◽  
Spectral Characteristics ◽  
Uv Absorption ◽  
Quantitative Detection ◽  
Gas Mixture ◽  
Uv Absorption Spectroscopy

As an alternative to sulfur hexafluoride (SF6) with great potential for application, heptafluoroisobutyronitrile–carbon dioxide (C4F7N–CO2) gas mixture has been applied in various gas-insulated equipment. The insulation performance of the gas mixture is closely related to the mixing ratio. Therefore, accurate quantification of C4F7N in the C4F7N–CO2 gas mixture has very important engineering significance. At present, there are few reports on the rapid quantitative detection of the concentration of C4F7N in the gas mixture. In this paper, a rapid analytical method for C4F7N concentration based on ultraviolet (UV) absorption spectroscopy is constructed. The UV spectral characteristics of C4F7N molecules are calculated by density functional theory. The appropriate bands that can be detected are determined by analyzing the calculated results. A concentration detection system of C4F7N based on UV absorption spectroscopy is built. Through analysis of the calculated results and experimental results, a quantitative detection method of C4F7N in the C4F7N/CO2 gas mixture is determined. The method can achieve accurate detection of the concentration of the gas mixture in the conventional application range (including 4–10% C4F7N). The coefficient of the determination R2 of the concentration inversion curve reaches 0.999 and the inversion error ratio does not exceed 5%. The related research results provide an important reference for the engineering application of the gas mixture.

scholarly journals Broadband Cavity Enhanced Differential Optical Absorption Spectroscopy (CE-DOAS) – applicability and corrections

2008 ◽  
Vol 1 (1) ◽  
pp. 481-507 ◽  
Author(s):  
U. Platt ◽  
J. Meinen ◽  
D. Pöhler ◽  
T. Leisner
Keyword(s):  
Absorption Spectroscopy ◽  
Broad Band ◽  
Gas Absorption ◽  
Trace Gas ◽  
Optical Absorption Spectroscopy ◽  
Light Sources ◽  
Light Path ◽  
Gas Concentration ◽  
Mirror Reflectivity ◽  
Gas Measurements

Abstract. Atmospheric trace gas measurements by cavity assisted long-path absorption spectroscopy are an emerging technology. An interesting approach is the combination of CEAS with broad band light sources, the broad-band CEAS (BB-CEAS). BB-CEAS lends itself to the application of the DOAS technique to analyse the derived absorption spectra. While the DOAS approach has enormous advantages in terms of sensitivity and specificity of the measurement, an important implication is the reduction of the light path by the trace gas absorption, since cavity losses due to absorption by gases reduce the quality (Q) of the cavity. In fact, at wavelength, where the quality of the BB-CEAS cavity is dominated by the trace gas absorption (esp. at very high mirror reflectivity), the light path will vary inversely with the trace gas concentration and the strength of the band will become nearly independent of the trace gas concentration c in the cavity, rendering the CEAS Method useless for trace gas measurements. Only in the limiting case where the mirror reflectivity determines Q at all wavelength, the strength of the band as seen by the BB-CEAS instrument becomes proportional to the concentration c. We investigate these relationships in detail and present methods to correct for the cases between the two above extremes, which are of course the important ones in practice.

scholarly journals A Cost-Effective Trace Gas Measurement Program for Long-Term Monitoring of the Stratospheric Circulation

2014 ◽  
Vol 95 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Fred L. Moore ◽  
Eric A. Ray ◽  
Karen H. Rosenlof ◽  
James W. Elkins ◽  
Pieter Tans ◽  
...  
Keyword(s):  
Cost Effective ◽  
Trace Gas ◽  
Gas Measurement ◽  
Stratospheric Circulation ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals Set up and application of an underwater Α-ray spectrometer for radioactivity measurements

2005 ◽  
Vol 6 (1) ◽  
pp. 35 ◽  
Author(s):  
C. TSABARIS ◽  
S. VLACHOS ◽  
C.T. PAPADOPOULOS ◽  
R. VLASTOU ◽  
C.A. KALFAS
Keyword(s):  
Marine Environment ◽  
Detection System ◽  
On Line ◽  
Parallel Measurement ◽  
Set Up ◽  
And Control ◽  
Potassium 40 ◽  
Radioactivity Measurements ◽  
Term Monitoring

The set up and control of an underwater measuring instrument for radioactivity pollution in the marine environment is described. The detection system is based on a NaI scintillator (RADAM III) with modifications for use in the marine environment with on-line measurements. The system is simple, has low power consumption and is stable for long-term monitoring (10 months). Before its deployment, the sensor was calibrated in the laboratory in a tank full of water to reproduce the marine environment. The calibrations were performed, by detecting the 661keV and 1461 keV gamma rays of known activity liquid sources 137 Cs and 40 K, respectively. The measured spectra in the laboratory were compared with spectra from a similar detector as acquired in the field. The analysis of the parallel measurement gave satisfactory agreement for the concentration of the potassium (40 K), as calculated from the salinity in the seawater, thus enabling the system for quantitative measurement of the seawater radioactivity.

The Design of Low Power Vibration Detection System Based on MEMS

2012 ◽  
Vol 588-589 ◽  
pp. 1132-1135
Author(s):  
Pan Xing ◽  
Guang Yu Ou ◽  
Gao Yi
Keyword(s):  
Low Power ◽  
Detection System ◽  
Mass Storage ◽  
Precision Data ◽  
Vibration Detection ◽  
High Precision Data ◽  
Long Term Monitoring ◽  
Mems Device ◽  
Term Monitoring

The Design of Low Power Vibration Detection System Based on a three-axis accelerometer MEMS device, which can perform many functions: making long-term monitoring on the shock intensity in both vertical and horizontal directions, recording the shock peak and waveform. The system with STM32 processor, high-precision data acquisition, mass storage, USB and so on. Based on FatFS file system, the system concerned with the bad block management problems in NandFlash will be optimized and thus the reliability of the system will also improve.

scholarly journals Long-Term Monitoring for Resistance of Botryotinia fuckeliana to Anilinopyrimidine, Phenylpyrrole, and Hydroxyanilide Fungicides in Switzerland

Plant Disease ◽  
2003 ◽  
Vol 87 (6) ◽  
pp. 662-666 ◽  
Author(s):  
Catherine A. Baroffio ◽  
Werner Siegfried ◽  
Urs W. Hilber
Keyword(s):  
Detection System ◽  
Field Isolate ◽  
Gray Mold ◽  
Field Resistance ◽  
Resistance Development ◽  
First Case ◽  
Long Term Monitoring ◽  
Botryotinia Fuckeliana ◽  
Term Monitoring

In Switzerland, the use of phenylpyrrole, anilinopyrimidine, and hydroxyanilide fungicides for control of Botryotinia fuckeliana, causal agent of gray mold in grapes, has been restricted to one treatment per fungicide class per year as part of an anti-resistance strategy. Resistance development in B. fuckeliana was monitored from 1995 to 2001 for the anilinopyrimidine cyprodinil and the phenylpyrrole fludioxonil and from 1997 to 2001 for the hydroxyanilide fenhexamid in experimental vineyards in Richterswil and Stäfa, Switzerland. In total, over 2,400 field isolates were tested. In 1996, the first case of field resistance to anilinopyrimidines was encountered in Richterswil. Efficacy of the anilinopyrimidine cyprodinil decreased significantly, and 54% of the isolates were resistant to anilinopyrimidines. During 7 years of monitoring, one field isolate was found that showed a slightly decreased sensitivity to the phenylpyrrole fludioxonil. Resistance to the hydroxyanilide fenhexamid was not found in 1997 and 1998. From 1999 to 2001, the level of fenhexamid-resistant isolates increased to 100% in Stäfa. The analysis of monitoring and efficacy data showed that subpopulations of B. fuckeliana resistant to cyprodinil and fenhexamid have increased significantly; however, the efficacy of a mixture of fludioxonil and cyprodinil and of fenhexamid alone was still effective. The objective of this study was to initiate long-term monitoring in order to establish an early resistance-detection system as a tool to assess the effectiveness of the anti-resistance strategy used in Switzerland.

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