Screen cell and method of using

• US 5,723,341 A
• Filed: 07/03/1996
• Issued: 03/03/1998
• Est. Priority Date: 02/25/1994
• Status: Expired due to Fees

• Current Assignee: Fluke Electronics Corporation (Fortive Corp.)
• Original Assignee: Janos Technology, Inc. (Danaher Corporation)
• Inventors: Truett, William L.
• Primary Examiner(s): Redding, David A.
• Application Number:
  US08/675,553
• Time in Patent Office: 608 Days
• Field of Search: 422/82.05, 422/102, 422/82.09, 422/104, 356/244, 356/246, 356/440, 446/15, 446/21, 446/16, D21/61, 250/459.1, 250/458.1, 436/165, 436/171, 436/174
• US Class Current: 436/171
• CPC Class Codes: G01N 2021/0346 Capillary cells; Microcells
• CPC Class Codes: G01N 21/03 Cuvette constructions
• CPC Class Codes: G01N 21/3563 for analysing solids; Preparation of samples therefor
• CPC Class Codes: Y10T 436/25 including sample preparation

Abstract

A method of analyzing a specimen by infrared spectroscopy is disclosed wherein a specimen support having a plurality of unobstructed holes of substantially uniform size and a film of the specimen enclosing each hole is positioned vertically in the spectrometer and a beam of infrared light is directed through the holes to generate a wavelength spectrum characteristic of the specimen.

Claims

1. A method of analyzing a specimen comprising the steps of forming a specimen support of a rigid material that is non-reactive to water, acidic substances and solvents having a pair of opposed surfaces and having a plurality of unobstructed holes in a rigid surface disposed between said pair of opposed surfaces, the axes of said holes being substantially perpendicular to said opposed surfaces;

enclosing each hole with an unsupported layer of a specimen to be analyzed, said specimen being selected from the group consisting of liquid, solid, paste or powder, said holes sized to retain a specimen to be analyzed enclosing said hole when said specimen support is positioned so that said opposed surfaces are vertical;

positioning said support so that the axes of said holes are horizontal;

directing a beam of infrared light through the holes and through the layer of said specimen enclosing each hole; and

generating a wavelength spectrum of said beam passing through said layer.

2. The method of claim 1 wherein said specimen is a liquid specimen.

3. The method of claim 1 wherein said specimen support comprises a pair of opposed surfaces having a plurality of unobstructed holes in a screen disposed between said pair of opposed surfaces.

4. The method of claim 2 wherein the largest dimension of each of said holes is in the range of 0.1 to about 2 mm.

5. The method of claim 1 wherein the largest dimension of each of said holes is in the range of 0.5 to about 1 mm.

6. The method of claim 1 wherein the cross-sectional area of each of said holes is in the range of 0.9 to 1.1 square millimeters.

7. An analytic specimen support for insertion in a spectrometer comprising a pair of opposed generally flat surfaces composed of rigid material that is non-reactive to water, acidic substances and solvents and having a plurality of unobstructed holes in a screen disposed between said pair of opposed, generally flat surfaces, the outer edges of said support being adapted to be placed vertically in said spectrometer;

the screen being positioned with respect to said surfaces such that when the support is placed vertically in a spectrometer the unobstructed holes are positioned in the path of the spectrometer beam;

the cross-sectional area of each hole is in the range of 0.01 to 4 mm² sufficient to retain about 0.1 microliter of liquid spanning said hole for at least 4 seconds when said screen is in a vertical position, the liquid being held in said hole by the surface tension of the liquid.

8. The support of claim 7 wherein the cross-sectional area of each of said holes is in the range of 0.25 to 1.1 mm².