BACKGROUND SUPPRESSION OF AR LINES IN GLOW-DISCHARGE ATOMIC EMISSION-SPECTROMETRY BY A LOCK-IN AMPLIFIER AND KALMAN FILTER DECONVOLUTION

1993-01-01
ULGEN, A
DOGAN, M
Gökmen, Ali
YALCIN, S
The Ar spectral lines are suppressed in Grimm-type glow discharge lamp atomic emission spectrometry (GDL-AES) by a double voltage modulation technique. The GDL is modulated between two voltage levels, typically 400 and 700 V. At the lower voltage level mainly Ar emission contributes whereas at the higher voltage level both Ar and atoms sputtered from the cathode contribute to the emission. The Ar emission spectrum at the lower voltage level is multiplied by a constant factor to scale it up to the same level of Ar emission found at the higher voltage level. This signal is then subtracted from the signal obtained at the higher voltage level by a lock-in amplifier to obtain the net analyte signal. The digital Kalman filter technique is also applied to background suppression; it is known to be the optimum filter for deconvolution of mixtures in noisy environments. The detection limits are found to be improved by nearly a factor of 10 with both double voltage modulation and Kalman filter techniques.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY

Suggestions

Micro processing by intense fast electron beam
Goktas, H; Kirkici, H; Oke, G; Udrea, M (2001-06-22)
Generation of intense electron beams by superposing two discharges, namely a low pressure do glow discharge and a high current pulsed discharge at pressures and voltages very similar to that of the pseudo-spark gap devices, has been reported previously [1, 2]. The small diameter, high peak current and short pulse length are the characteristics of the electron beam generated using this technique. In this technique, no high vacuum facilities are necessary, and many applications such as micro processing, X-ray...
A photon counting dynamic digital lock-in amplifier for background suppression in glow discharge atomic emission spectrometry
Gokmen, A; Ulgen, A; Yalcin, S (1996-01-15)
A photon counting dynamic digital lock-in amplifier, (PC-DDLIA), has been developed for the suppression of Ar lines in glow discharge lamp atomic emission spectrometry, (GDL-AES). The experimental set-up consists of a Grimm-type GDL, a prism-type scanning monochromator, photon counting electronics, an Apple Ile computer with an interface card and a computer controllable high voltage power supply. The photon counting electronics are designed to convert the photon pulses to logic pulses. A discriminator is us...
Investigation of nonlinear oscillations in the gas discharge-semiconductor system: effect of different fluid modelling approaches
Yeşil, Cihan; Rafatov, İsmail; Department of Physics (2018)
The work deals with the study of nonlinear oscillations in a system, consisted of planar glow discharge layer, coupled to a high-ohmic semiconductor layer. The whole system is sandwiched between two planar electrodes, to which the DC voltage is applied. The discharge models are developed in Comsol Multiphysics (v5.2), and based on fluid description of plasma, with drift-diffusion approximation for charged particle fluxes. Numerical tests are carried out for the discharge in Nitrogen, with GaAs semiconductor la...
Spatiotemporal patterns in a dc semiconductor-gas-discharge system: Stability analysis and full numerical solutions
Rafatov, İsmail; EBERT, Ute (American Physical Society (APS), 2007-09-01)
A system very similar to a dielectric barrier discharge, but with a simple stationary dc voltage, can be realized by sandwiching a gas discharge and a high-ohmic semiconductor layer between two planar electrodes. In experiments this system forms spatiotemporal and temporal patterns spontaneously, quite similarly to, e.g., Rayleigh-Benard convection. Here it is modeled with a simple discharge model with space charge effects, and the semiconductor is approximated as a linear conductor. In previous work, this ...
Near-infrared emission spectrometry measurements for nonintrusive soot diagnostics in flames
Ayranci, Isil; Vaillon, Rodolphe; Selçuk, Nevin (2008-01-01)
The present study focuses on measurement of line-of-sight emission intensity spectra in the near-infrared range by Fourier-transform infrared spectrometry for use in tomographic soot diagnostics. Measurements are carried out on an axisymmetric, laboratory grade, ethylene/air diffusion flame within the 1.1-1.7 mu m (9000-6000 cm(-1)) spectral range. Presentation of the measurement and calibration methodology is followed by the description of noise and uncertainty assessment procedures. A novel noise characte...
Citation Formats
A. ULGEN, M. DOGAN, A. Gökmen, and S. YALCIN, “BACKGROUND SUPPRESSION OF AR LINES IN GLOW-DISCHARGE ATOMIC EMISSION-SPECTROMETRY BY A LOCK-IN AMPLIFIER AND KALMAN FILTER DECONVOLUTION,” SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY, pp. 65–78, 1993, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/62897.