Absorbance, turbidimetric, fluorescence and nephelometric photometer

• US 4,730,922 A
• Filed: 05/08/1985
• Issued: 03/15/1988
• Est. Priority Date: 05/08/1985
• Status: Expired due to Term

• Current Assignee: Dade Behring, Inc. (Siemens AG)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Bach, David T., Robertson, Charles W. Jr.
• Primary Examiner(s): Evans, F. L.
• Application Number:
  US06/731,781
• Time in Patent Office: 1,042 Days
• Field of Search: 356/73, 356/326, 356/328, 356/317, 356/318, 356/244, 356/246, 250/365, 250/458.1, 250/459.1, 250/461.1, 250/461.2
• US Class Current: 356/73
• CPC Class Codes: G01J 3/1838 Holographic gratings
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01N 2021/1738 Optionally different kinds of measurements; Method being valid for different kinds of measurement
• CPC Class Codes: G01N 2021/6482 Sample cells, cuvettes
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/17 Systems in which incident light is modified in accordance with the properties of the material investigated where the material investigated is optically excited causing a change in wavelength of the incident light G01N21/63
• CPC Class Codes: G01N 21/51 inside a container, e.g. in an ampoule G01N21/53 takes precedence
• CPC Class Codes: G01N 21/59 Transmissivity G01N21/25 takes precedence
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G01N 2201/0696 Pulsed

Abstract

An absorbance, turbidimetric, fluorescence, and nephelometric photometer is constructed by providing a sample cell having a rectangular absorbance/turbidimetric cross-section for radiation. The cells exit aperture is positioned to be the entrance aperture for a grating which separates the light according to wavelength and impingement on an array detector.

Claims

1. In a multi-function photometer having a sample cell for containing a liquid to be measured, a grating, an array of photodiodes, and a source of radiation directed along a first axis through the cell to the grating for dispersing the radiation according to wavelength onto respective different ones of the photodiodes, thereby to provide output signals corresponding to the intensity of radiation at each wavelength, the improvement wherein the sample cell defines an exit aperture perpendicular to the first axis, the exit aperture being positioned to be the entrance aperture for the grating.

2. The photometer set forth in claim 1 wherein the sample cell has a rectangular cross-section perpendicular to the first axis that is larger in all dimensions than the exit aperture cross-section.

3. The photometer set forth in claim 2 which includes a second source of radiation directed along a second axis perpendicular to the first axis for exciting fluorescence of liquid in the sample cell, the sample cell having a fluorescent entrance aperture lying on the second axis, the fluorescent radiation exiting the cell through the grating entrance aperture.

4. The photometer set forth in claim 3 wherein the cross-sectional area of the fluorescence entrance aperture is greater than the cross-sectional area of the cell along the first axis.

5. The photometer set forth in claim 4 which includes a straylight filter disposed between the grating and the photodiode array, the filter having two filer sections, one selected to pass exciting radiation from the second source, the other selected to pass the fluorescent radiation to match that of fluorophores used in the liuqid sample.

6. The photometer set forth in claim 5 which also includes means for scanning the several output signals to obtain a wavelength related distribution of radiation intensities emitted from the sample cell.

7. The photometer set forth in claim 1 which includes a second source of radiation directed along a second axis perpendicular to the first axis for exciting fluorescence of liuqid in the sample cell, the sample cell having a fluorescent entrance aperture lying on the second axis, the fluorescent radiation exiting the cell through the grating entrance aperture.

8. The photometer set forth in claim 7 wherein the cross-sectional area of the fluorescence entrance aperture is greater than the cross-sectional area of the cell along the first axis.

9. The photometer set forth in claim 1 which includes a second source of radiation directed along a second axis perpendicular to the first axis for exciting fluorescence of liquid in the sample cell, the sample cell having a fluorescent entrance aperture lying on the second axis, the fluorescent radiation exiting the cell through the grating entrance aperture and a straylight filter disposed between the grating and photodiode array, the filter having two filter sections, one selected to pass exciting radiation from the second source, the other selected to pass the fluorescent radiation to match that of fluorophores used in the liquid sample.

10. The photometer set forth in claim 3 which includes a straylight filter disposed between the grating and the photodiode array, the filter having two filter sections, one selected to pass exciting radiation from the second source, the other selected to pass the fluorescent radiation to match that of fluorphores used in the liquid sample.