Background correction in spectro-chemical analysis

Claim 3

The method of claim 1 wherein the magnetic field applied to said sample is varied between different magnetic intensities.

Claim 4

The method of claim 1 wherein the magnetic field applied to said sample is periodically varied between different magnetic intensities.

Claim 5

The method of claim 1 wherein the incident beam of plane polarized light is polarized at an angle of 45° from the magnetic field about the optical axis.

Claim 6

The method of claim 1 wherein the magnetic field applied to the sample transverse to said optical axis is maintained constant, the polarization angle of the incident beam of plane polarized light is rotated about the optical axis, and the polarizer is rotated synchronously with the incident beam rotation, while maintaining a crossed relationship therebetween.

Claim 7

Apparatus for providing a background corrected measure of the concentration of a sample element, by magnetic double refraction, comprising: (a) means for providing the sample element in a gaseous state on the optical axis, the element having a given optical resonance wavelength, (b) means for subjecting the sample to a magnetic field transverse to said optical axis, (c) means for supplying and directing at the sample and along the optical axis a beam of plane polarized light having said resonance wavelength, at least at a given time said beam of plane polarized light being polarized at such an angle relative to the transverse magnetic field as to cause the light at the sample to divide into two components, one component having its electric vector parallel to the field and the other component having its electric vector perpendicular to the field, said components forming a single polarized beam upon emergence from the sample having a polarization angle different from that of the incident beam of polarized light, (d) a polarizer on said optical axis crossed with respect to the polarization of said incident beam of plane polarized light and positioned to interrupt said emergent beam from the sample, and (e) means responsive to the differential intensity of the emergent beam after passing through said polarizer at said given time and at some other time for providing a measure of the sample element concentration.

Claim 8

Apparatus for providing a background corrected measure of the concentration of a sample element, by magnetic double refraction, comprising: (a) means for providing the sample element in a gaseous state on the optical axis, the element having a given optical resonance wavelength, (b) means for subjecting the sample to a magnetic field transverse to said optical axis, (c) means for supplying and directing at the sample and along the optical axis a beam of plane polarized light having said resonance wavelength, at least at a given time said beam of plane polarized light being polarized at such an angle relative to the transverse magnetic field as to cause the light at the sample to divide into two components, one component having its electric vector parallel to the field and the other component having its electric vector perpendicular to the field, said components forming a single polarized beam upon emergence from the sample having a polarization angle different from that of the incident beam of polarized light, (d) a polarizer on said optical axis crossed with respect to the polarization of said incident beam of plane polarized light and positioned to interrupt said emergent beam from the sample, and (e) means responsive to the differential intensity of the emergent beam after passing through said polarizer at said given time and at some other time for providing a measure of the sample element concentration.

Claim 9

The apparatus of claim 6 wherein said means for subjecting the sample to a magnetic field comprises means for varying the magnetic field applied to the sample between different magnetic intensities.

Claim 10

The apparatus of claim 7 wherein the variation of the magnetic field is periodic.

Claim 11

The apparatus of claim 6 wherein the magnetic field perpendicular to said optical axis is oriented at 45° to the polarization angle of the incident beam of plane polarized light.

Claim 12

The apparatus of claim 6 comprising means for rotating the plane of polarization of the incident beam of plane polarized light about said optical axis and means for synchronously rotating said polarizer to maintain said crossed relationship.