High accuracy absorbance spectrophotometers
First Claim
1. A spectrophotometer comprising:
- a first light source configured to emit a first emission spectrum that spans a first wavelength range, the first emission spectrum comprising a plurality of characteristic atomic emissions;
a second light source configured to emit a second emission spectrum that spans a second wavelength range;
a beam splitter configured to combine light emitted from the first light source with light emitted from the second light source and split the combined light to form a sample beam and a reference beam;
a sample cell downstream of and in optical communication with the beam splitter;
a sample spectrometer downstream of and in optical communication with the sample cell;
a reference spectrometer downstream of and in optical communication with the beam splitter; and
a processor in communication with the sample spectrometer and the reference spectrometer, the processor being configured to map the characteristic atomic emissions of the first light source to a first set of responses of the sample spectrometer and to a second set of responses of the reference spectrometer, the processor being further configured to compare and interpolate the first set of responses with the second set of responses and to thereby obtain a correction function, the processor being further configured to apply the correction function to raw sample data communicated to the processor from the sample spectrometer and the reference spectrometer.
3 Assignments
0 Petitions
Accused Products
Abstract
Spectrophotometers and spectroscopy processes are described that can provide for in-line calibration at every spectral acquisition as well as for continuous response correction during sample processing. The spectrophotometers include multiple polychromatic light sources that include characteristic emission spectra for use as an internal wavelength drift calibration system that is independent of environmental factors. Correction functions provided by the internal calibration process can be applied continuously and across an entire sample spectrum. The intensity response of each spectrometer in a spectrophotometer can also be monitored and continuously corrected for stray light, dark current, readout noise, etc.
23 Citations
20 Claims
-
1. A spectrophotometer comprising:
-
a first light source configured to emit a first emission spectrum that spans a first wavelength range, the first emission spectrum comprising a plurality of characteristic atomic emissions; a second light source configured to emit a second emission spectrum that spans a second wavelength range; a beam splitter configured to combine light emitted from the first light source with light emitted from the second light source and split the combined light to form a sample beam and a reference beam; a sample cell downstream of and in optical communication with the beam splitter; a sample spectrometer downstream of and in optical communication with the sample cell; a reference spectrometer downstream of and in optical communication with the beam splitter; and a processor in communication with the sample spectrometer and the reference spectrometer, the processor being configured to map the characteristic atomic emissions of the first light source to a first set of responses of the sample spectrometer and to a second set of responses of the reference spectrometer, the processor being further configured to compare and interpolate the first set of responses with the second set of responses and to thereby obtain a correction function, the processor being further configured to apply the correction function to raw sample data communicated to the processor from the sample spectrometer and the reference spectrometer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for determining an absorbance spectrum, the method comprising:
-
combining a first emission spectrum of a first light source with a second emission spectrum of a second light source to form a combined spectra, the first emission spectrum comprising a plurality of characteristic atomic emissions; splitting the combined spectra to form a sample beam and a reference beam; directing the sample beam through a sample cell and to a sample spectrometer, the sample spectrometer developing a first data set in response to the sample beam; directing the reference beam to a reference spectrometer, the reference spectrometer developing a second data set in response to the reference beam; communicating the first and second data sets to a processor, the processor mapping the characteristic atomic emissions of the first light source to the first data set and to the second data set, the processor further comparing and interpolating the results of the mapping and thereby obtaining a correction function. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification