Optical emission line monitor with background observation and cancellation
Abstract
A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the emission line to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the emission line of interest detected by themore »
- Inventors:
-
- Star City, WV
- Morgantown, WV
- Issue Date:
- Research Org.:
- National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States)
- OSTI Identifier:
- 866008
- Patent Number(s):
- 4616137
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Classifications (CPCs):
-
F - MECHANICAL ENGINEERING F23 - COMBUSTION APPARATUS F23N - REGULATING OR CONTROLLING COMBUSTION
G - PHYSICS G01 - MEASURING G01J - MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED, VISIBLE OR ULTRA-VIOLET LIGHT
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- optical; emission; line; monitor; background; observation; cancellation; fiber; optics; based; monitoring; provided; selected; spectral; lines; sodium; d-line; coal; combustion; detected; presence; interferring; blackbody; radiation; emissions; intensity; bifurcated; optic; light; guide; adapted; branch; view; guided; bandpass; filter; common; trunk; portion; reflected; centered; wavelength; corresponding; bandwidth; nanometers; nm; width; 10; detectors; located; passing; filters; respectively; detector; blind; difference; outputs; uniquely; indicative; flame; instrument; reduce; effects; 20; db; selected spectral; light detectors; detector output; bandpass filter; coal combustion; fiber optics; fiber optic; light guide; emission line; optic light; blackbody radiation; light detector; pass filter; light passing; spectral emission; optical emission; flame emission; emission lines; line emission; optics based; detector outputs; based optical; line monitoring; /250/340/356/431/
Citation Formats
Goff, David R, and Notestein, John E. Optical emission line monitor with background observation and cancellation. United States: N. p., 1986.
Web.
Goff, David R, & Notestein, John E. Optical emission line monitor with background observation and cancellation. United States.
Goff, David R, and Notestein, John E. Wed .
"Optical emission line monitor with background observation and cancellation". United States. https://www.osti.gov/servlets/purl/866008.
@article{osti_866008,
title = {Optical emission line monitor with background observation and cancellation},
author = {Goff, David R and Notestein, John E},
abstractNote = {A fiber optics based optical emission line monitoring system is provided in which selected spectral emission lines, such as the sodium D-line emission in coal combustion, may be detected in the presence of interferring background or blackbody radiation with emissions much greater in intensity than that of the emission line being detected. A bifurcated fiber optic light guide is adapted at the end of one branch to view the combustion light which is guided to a first bandpass filter, adapted to the common trunk end of the fiber. A portion of the light is reflected back through the common trunk portion of the fiber to a second bandpass filter adapted to the end of the other branch of the fiber. The first filter bandpass is centered at a wavelength corresponding to the emission line to be detected with a bandwidth of about three nanometers (nm). The second filter is centered at the same wavelength but having a width of about 10 nm. First and second light detectors are located to view the light passing through the first and second filters respectively. Thus, the second detector is blind to the light corresponding to the emission line of interest detected by the first detector and the difference between the two detector outputs is uniquely indicative of the intensity of only the combustion flame emission of interest. This instrument can reduce the effects of interferring blackbody radiation by greater than 20 dB.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1986},
month = {1}
}