Method for improving instrument response
Abstract
This invention pertains generally to a method for improving the accuracy of particle analysis under conditions of discrete particle loading and particularly to a method for improving signal-to-noise ratio and instrument response in laser spark spectroscopic analysis of particulate emissions. Under conditions of low particle density loading (particles/m.sup.3) resulting from low overall metal concentrations and/or large particle size uniform sampling can not be guaranteed. The present invention discloses a technique for separating laser sparks that arise from sample particles from those that do not; that is, a process for systematically "gating" the instrument response arising from "sampled" particles from those responses which do not, is dislosed as a solution to his problem. The disclosed approach is based on random sampling combined with a conditional analysis of each pulse. A threshold value is determined for the ratio of the intensity of a spectral line for a given element to a baseline region. If the threshold value is exceeded, the pulse is classified as a "hit" and that data is collected and an average spectrum is generated from an arithmetic average of "hits". The true metal concentration is determined from the averaged spectrum.
- Inventors:
-
- 7528 Oxford Cir., Dublin, Alameda County, CA 94568
- 2665 Calle Alegre, Pleasanton, Alameda County, CA 94566
- 5443 Celeste Ave., Livermore, Alameda County, CA 94550
- 5447 Theresa Way, Livermore, Alameda County, CA 94550
- Issue Date:
- Research Org.:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- OSTI Identifier:
- 872993
- Patent Number(s):
- 6061641
- Assignee:
- Hahn, David W. (7528 Oxford Cir., Dublin, Alameda County, CA 94568);Hencken, Kenneth R. (2665 Calle Alegre, Pleasanton, Alameda County, CA 94566);Johnsen, Howard A. (5443 Celeste Ave., Livermore, Alameda County, CA 94550);Flower, William L. (5447 Theresa Way, Livermore, Alameda County, CA 94550)
- Patent Classifications (CPCs):
-
G - PHYSICS G01 - MEASURING G01J - MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT
- DOE Contract Number:
- AC04-94AL85000
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- method; improving; instrument; response; pertains; accuracy; particle; analysis; conditions; discrete; loading; particularly; signal-to-noise; ratio; laser; spark; spectroscopic; particulate; emissions; density; particles; resulting; overall; metal; concentrations; size; uniform; sampling; guaranteed; discloses; technique; separating; sparks; arise; sample; process; systematically; gating; arising; sampled; responses; dislosed; solution; disclosed; approach; based; random; combined; conditional; pulse; threshold; value; determined; intensity; spectral; line; element; baseline; region; exceeded; classified; hit; data; collected; average; spectrum; generated; arithmetic; hits; true; concentration; averaged; particulate emissions; laser spark; threshold value; spectral line; spectroscopic analysis; signal-to-noise ratio; particle size; noise ratio; metal concentrations; particle analysis; metal concentration; particulate emission; size uniform; /702/356/
Citation Formats
Hahn, David W, Hencken, Kenneth R, Johnsen, Howard A, and Flower, William L. Method for improving instrument response. United States: N. p., 2000.
Web.
Hahn, David W, Hencken, Kenneth R, Johnsen, Howard A, & Flower, William L. Method for improving instrument response. United States.
Hahn, David W, Hencken, Kenneth R, Johnsen, Howard A, and Flower, William L. Sat .
"Method for improving instrument response". United States. https://www.osti.gov/servlets/purl/872993.
@article{osti_872993,
title = {Method for improving instrument response},
author = {Hahn, David W and Hencken, Kenneth R and Johnsen, Howard A and Flower, William L},
abstractNote = {This invention pertains generally to a method for improving the accuracy of particle analysis under conditions of discrete particle loading and particularly to a method for improving signal-to-noise ratio and instrument response in laser spark spectroscopic analysis of particulate emissions. Under conditions of low particle density loading (particles/m.sup.3) resulting from low overall metal concentrations and/or large particle size uniform sampling can not be guaranteed. The present invention discloses a technique for separating laser sparks that arise from sample particles from those that do not; that is, a process for systematically "gating" the instrument response arising from "sampled" particles from those responses which do not, is dislosed as a solution to his problem. The disclosed approach is based on random sampling combined with a conditional analysis of each pulse. A threshold value is determined for the ratio of the intensity of a spectral line for a given element to a baseline region. If the threshold value is exceeded, the pulse is classified as a "hit" and that data is collected and an average spectrum is generated from an arithmetic average of "hits". The true metal concentration is determined from the averaged spectrum.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {1}
}
Works referenced in this record:
Real-time optical measurement of alkali species in air for jet engine corrosion testing
conference, February 2013
- Holtzclaw, K.; Moore, J.; Senior, C.
- 31st Aerospace Sciences Meeting