254 nm Radiant Efficiency of High Output Low Pressure Mercury Discharge Lamps with Neon-Argon Buffer Gas

Zhang, Hao Jun; Han, Qiu Yi; Zhang, Shan Duan

doi:10.4028/www.scientific.net/amm.325-326.409

Cited by 3 publications

(4 citation statements)

References 7 publications

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“…Low-pressure Hg lamps have been studied and reviewed in detail before. − Briefly, in the gas discharge, electrons are produced and accelerated by the electric field. During their travel in the lamp, the collisions with Hg atoms result in kinetic energy transfer from the electrons to Hg atoms.…”

Section: Introductionmentioning

confidence: 99%

Modeling the Radical Chemistry in an Oxidation Flow Reactor: Radical Formation and Recycling, Sensitivities, and the OH Exposure Estimation Equation

Palm²,

Ortega³

et al. 2015

J. Phys. Chem. A

166

203

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Oxidation flow reactors (OFRs) containing low-pressure mercury (Hg) lamps that emit UV light at both 185 and 254 nm ("OFR185") to generate OH radicals and O3 are used in many areas of atmospheric science and in pollution control devices. The widely used potential aerosol mass (PAM) OFR was designed for studies on the formation and oxidation of secondary organic aerosols (SOA), allowing for a wide range of oxidant exposures and short experiment duration with reduced wall loss effects. Although fundamental photochemical and kinetic data applicable to these reactors are available, the radical chemistry and its sensitivities have not been modeled in detail before; thus, experimental verification of our understanding of this chemistry has been very limited. To better understand the chemistry in the OFR185, a model has been developed to simulate the formation, recycling, and destruction of radicals and to allow the quantification of OH exposure (OHexp) in the reactor and its sensitivities. The model outputs of OHexp were evaluated against laboratory calibration experiments by estimating OHexp from trace gas removal and were shown to agree within a factor of 2. A sensitivity study was performed to characterize the dependence of the OHexp, HO2/OH ratio, and O3 and H2O2 output concentrations on reactor parameters. OHexp is strongly affected by the UV photon flux, absolute humidity, reactor residence time, and the OH reactivity (OHR) of the sampled air, and more weakly by pressure and temperature. OHexp can be strongly suppressed by high OHR, especially under low UV light conditions. A OHexp estimation equation as a function of easily measurable quantities was shown to reproduce model results within 10% (average absolute value of the relative errors) over the whole operating range of the reactor. OHexp from the estimation equation was compared with measurements in several field campaigns and shows agreement within a factor of 3. The improved understanding of the OFR185 and quantification of OHexp resulting from this work further establish the usefulness of such reactors for research studies, especially where quantifying the oxidation exposure is important.

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Section: Introductionmentioning

confidence: 99%

Modeling the Radical Chemistry in an Oxidation Flow Reactor: Radical Formation and Recycling, Sensitivities, and the OH Exposure Estimation Equation

Palm²,

Ortega³

et al. 2015

J. Phys. Chem. A

166

203

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“…When the cold spot temperature increases to 40 °C or above, the lamp has a high mercury pressure and the mercury discharge accounts for the major part of the radiation. However, the main radiation of mercury in 185 nm (η185 ~ 10%) and 254 nm (η254 ~ 40%) begin to drop at the cold spot temperature about 70 °C and 45 °C respectively [6,7] , so the input power declines at a higher cold spot temperature. Although the low pressure mercury lamps have negative resistance characteristics which lead to a decrease of the electric field with increasing current, the increase of the current is more significant than the decrease of the electric field.…”

Section: B Measurementsmentioning

confidence: 99%

“…Koedam et al measured the radiance of spectral lines in the positive column of T12 Ar-Hg lamp, calculated the radiant power of each line by introducing the Koedam factor, and analysed the energy balance in the positive column [5] . Zhang et al studied the 254 nm radiant characteristics of T6 high output low pressure mercury lamp on radiant efficiency and the discharge parameters, obtained the optimum cold spot temperature at 45-48 °C when the highest 254 nm radiant efficiency reached more than 40% [6,7] . Besides, the radiant efficiency decreases with the increases of the current and buffer gas pressure.…”

Section: Introductionmentioning

confidence: 99%

185 nm radiation measurement of high output low pressure mercury lamps

An¹,

Han²,

Zhang³

2015

Proceedings of the 2015 International Conference on Mechatronics, Electronic, Industrial and Control Engineering

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Abstract-For many years the low pressure mercury lamps are widely used in general lighting and ultraviolet radiation. Because of its strong 254 nm ultraviolet and 185 nm vacuum ultraviolet radiation, it has played a very active role in environment, agriculture and medical fields. In environmental treatments, 254 nm radiation has been used for disinfecting the air and water, while the 185 nm radiation is applied to the degradation of organic matter. In this paper, the 185 nm radiation of high output low pressure mercury lamp, with 80 cm in length, was measured in a customized vacuum chamber based on Keitz method. The radiant characteristics of the lamp was discussed, indicating that the 185 nm radiant efficiency reached the maximum of 11% at the cold spot temperature 70 °C while it is negatively related to the discharge current.

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“…Usual UV excitation includes deuterium lamp [15], xenon lamp [16] and neon lamp [17]. However, such excitation depends on an electrode to launch electron and excite gas discharge.…”

Section: Introductionmentioning

confidence: 99%

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

Chen

et al. 2021

Sensors

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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.

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254 nm Radiant Efficiency of High Output Low Pressure Mercury Discharge Lamps with Neon-Argon Buffer Gas

Cited by 3 publications

References 7 publications

Modeling the Radical Chemistry in an Oxidation Flow Reactor: Radical Formation and Recycling, Sensitivities, and the OH Exposure Estimation Equation

Modeling the Radical Chemistry in an Oxidation Flow Reactor: Radical Formation and Recycling, Sensitivities, and the OH Exposure Estimation Equation

185 nm radiation measurement of high output low pressure mercury lamps

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

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