System and method for spectral analysis

• US 6,670,613 B2
• Filed: 04/26/2001
• Issued: 12/30/2003
• Est. Priority Date: 04/28/2000
• Status: Expired due to Term

• Current Assignee: Bacharach Inc. (MSA Safety, Inc.)
• Original Assignee: Bacharach Inc. (MSA Safety, Inc.)
• Inventors: McLane, Allan Jr., Prozzo, Christopher D.
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Sung, Christine
• Application Number:
  US09/842,431
• Publication Number:
  US 20010045521A1
• Time in Patent Office: 978 Days
• Field of Search: 250/345, 250/343, 250/338.1, 250/336.1
• US Class Current: 250/345
• CPC Class Codes: G01N 21/3151 using two sources of radiation of different wavelengths G01N21/33 - G01N21/39 take precedence
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis

Abstract

A method and system for identifying and calculating the percentages of gases, such as the automotive and other commercial refrigerant gases, in a gas mixture using infrared spectroscopy is disclosed. The novel system is compact, relatively inexpensive and has greater accuracy than those systems of the prior art.

Claims

1. A system for identifying and analyzing the amounts of individual refrigerants in a mixture of refrigerant components and contaminants comprising:

(1) a plurality of test areas or gas cells adapted to contain samples of said mixture;

(2) a plurality of infrared light sources adapted to project light through each of said cells;

(3) a plurality of light filters placed either before or after said cells containing said samples, each filter adapted to provide a predetermined wavelength range of infrared light corresponding to one of the refrigerant components in said mixture;

(4) a plurality of light detectors calibrated to sense the infrared absorbance of the impinging light and adapted to provide a signal corresponding to the percentage by volume of each of the individual refrigerant components of said mixture;

(5) means to measure pressure and temperature of samples being analyzed, wherein said pressure is measured relative to atmospheric pressure; and

(6) means for determining the presence and amount of a contaminant which is not detected optically, as a function of the measured pressure and temperature of the samples being analyzed.

2. The system of claim 1, wherein the contaminant is air.