US 4,832,491 A · Method of and apparatus for spectroscopically analyzing samples

Abstract

A single beam wavelength scanning spectrophotometer comprises means for passing radiation from a radiation source (1) to a radiation detector (4) over a defined path which includes a monochromator (2) capable of being scanned across a selected wavelength range, means (7) for storing a first set of signals representative of the radiation falling on the radiation detector, the first set of signals being spread across the selected wavelength range to form a first spectral response, means for inserting a sample (3) in the defined path, means for producing a second set of signals representative of the radiation falling on the radiation detector when the sample (3) is inserted in the defined path, the second set of signals being spread across a selected wavelength range to form a second spectral response, and means (7) for calculating the transmittance or absorbance of the sample at desired wavelengths from the first and second spectral responses. The ambient temperature in the region of the radiation detector (5) is monitored (6) and the first and/or second sets of signals are modified in dependence on the ambient temperature when the first and second set of signals are produced.

Claims23

Dependent claims

A method of analyzing one or more samples in succession with a single beam wavelength scanning spectrophotometer comprising the steps of

(a) passing radiation from a radiation source to a radiation detector over a defined optical path, said path including a wavelength selective element, said wavelength selective element being scanned over a selected wavelength range,
(b) storing a first set of signals representative of radiation passing to said radiation detector, said first set of signals being spread over said selected wavelength range to form a first spectral response,
(c) inserting a sample in said defined optical path,
(d) producing a second set of signals representative of radiation through said sample to said radiation detector, said second set of signals being spread over a second selected wavelengths range to form a second spectral response,
(e) calculating absorbance or transmittance of said sample at predetermined wavelengths using said first and second spectral responses,
(f) repeating said steps (c) through (e) for each successive different sample,
(g) monitoring ambient temperature in the region of said radiation detector, and
(h) modifying at least one of said first or said second sets of signals according to ambient temperature when said first and said second sets of signals are produced.

5 more elements

A single beam wavelength scanning spectrophotometer comprising

first means for passing radiation from a radiation source to a radiation detector over a defined path, said first means including a wavelength selective element capable of being scanned across a selected wavelength range,
second means for storing a first set of signals representative of radiation striking said radiation detector, said first set of signals being spread over said selected wavelength range to form a first spectral response,
third means for inserting a sample in said defined path,
fourth means for producing a second set of signals representative of radiation striking said radiation detector when said sample is inserted in said defined path, said second set of signals being spread over a second selected wavelength range to form a second spectral response,
fifth means for calculating transmittance or absorbance of said sample at predetermined wavelengths of said first and second spectral response,
sixth means for monitoring ambient temperature in the region of said radiation detector, and
seventh means for modifying at least one of said first and second second sets of signals according to ambient temperature when said first and said second sets of signals are produced.

4 more elements

Dependencies are inferred from the claim text.

Method of and apparatus for spectroscopically analyzing samples

Life of this patent

Method of and apparatus for spectroscopically analyzing samples

Life of this patent

Abstract

Claims23