Abstract The present disclosure relates to spectrometry. A method is disclosed for detecting nitric oxide (NO) without first converting it to nitrogen dioxide (NO2) by determining the intensity of a spectral signature in the range between about 2259 and 2269 Angstroms. Apparatus is provided which, in one form, utilizes an output shutter arrangement having a plurality of reciprocating vanes operated at mutually exclusive frequencies for passing regions of absorption radiation and continuum radiation. Circuit means is provided for distinguishing the signals derived at the various frequencies to determine the relative amount of particular material in a sample. In another form of the invention, an output chopper is provided having at least three slit apertures, the center aperture being adapted to pass only radiation at an absorption wavelength and the two outer apertures being adapted to pass radiation in the continuum. A vane is adapted to reciprocate between a first position wherein the chopper passes only radiation through the center aperture and a second position wherein the chopper passes only radiation through the two outer apertures. The area of each of the two outer apertures is preferably one-half the area of the center aperture. A detector viewing radiation passed by the chopper will average the radiation received from the two outer apertures. In yet another aspect of the invention, a window assembly is provided so that the spectrometer may be used as a stack monitor, the window assembly having a slidable window which may be removed for cleaning purposes.
Inventors
👤 D Egan
👤 G Holstrom
👤 H Lord
👤 R Howard
👤 R Stevens
👤 D Port
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-07 10:44
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/85
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
212 words
A window assembly for use with a stack monitor for monitoring materials present in fluid flowing through the stack, said window assembly comprising housing means having a forward wall containing a first aperture and a rear wall containing a second aperture, said first aperture being adapted to be positioned in fluid communication with a region of the stack through which said fluid flows; a recess in the forward face of said forward wall, in communication with a downstream edge of said first aperture; said rear wall containing a slot at said second aperture so that there is provided a line of sight through said first and second apertures slide means having a body and a transparent portion, said slide means being slidably engaged in said slot and slidably movable between a first position wherein said transparent portion is positioned between said first and second apertures, and a second position wherein said body blocks the line of sight between said first and second apertures and blower means connected with said housing for directing fluid through said first aperture into said region, whereby fluid flowing from the housing through said first aperture forms a fluid barrier in said stack region with fluid flowing through said stack of said region, and fluid turbulence is reduced.
Claim 2
Dependent Claim
212 words
A window assembly for use with a stack monitor for monitoring materials present in fluid flowing through the stack, said window assembly comprising housing means having a forward wall containing a first aperture and a rear wall containing a second aperture, said first aperture being adapted to be positioned in fluid communication with a region of the stack through which said fluid flows; a recess in the forward face of said forward wall, in communication with a downstream edge of said first aperture; said rear wall containing a slot at said second aperture so that there is provided a line of sight through said first and second apertures slide means having a body and a transparent portion, said slide means being slidably engaged in said slot and slidably movable between a first position wherein said transparent portion is positioned between said first and second apertures, and a second position wherein said body blocks the line of sight between said first and second apertures and blower means connected with said housing for directing fluid through said first aperture into said region, whereby fluid flowing from the housing through said first aperture forms a fluid barrier in said stack region with fluid flowing through said stack of said region, and fluid turbulence is reduced.
Claim 3
Dependent Claim
23 words
Apparatus according to claim 1 further including seal means providing a fluid seal between said slide means and said housing in said slot.
Claim 4
Dependent Claim
22 words
A window assembly according to claim 1 in which said recess recedes rearwardly in the direction of fluid flow through said stack.