Apparatus for analyzing the carbon content of metals

• US 4,332,770 A
• Filed: 10/21/1980
• Issued: 06/01/1982
• Est. Priority Date: 11/17/1979
• Status: Expired due to Term

• Current Assignee: Horiba Limited
• Original Assignee: Horiba Limited
• Inventors: Ishida, Kozo, Kira, Akimichi
• Primary Examiner(s): Serwin, Ronald E.
• Application Number:
  US06/199,217
• Time in Patent Office: 588 Days
• Field of Search: 422/78, 422/80, 23/230 PC, 23/232 R, 356/229, 356/437, 356/418
• US Class Current: 422/78
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 31/12 using combustion G01N25/20 takes precedence
• CPC Class Codes: G01N 33/2022 Non-metallic constituents
• CPC Class Codes: Y10T 436/23 Carbon containing

Abstract

An apparatus for analyzing carbon in metals, in which a metallic sample is burned in a current of oxygen in a combustion furnace and the concentration of carbon contained in the metallic sample is calculated from the total concentration of carbon monoxide and carbon dioxide in the gas generated in the combustion furnace, the concentration determined by means of a non-dispersive infrared analyzer. The non-dispersive infrared analyzer is provided with a detector which exhibits almost the same sensitivity to both carbon monoxide and carbon dioxide.

Claims

1. An apparatus for analyzing the carbon content of a metallic sample by utilizing a furnace for burning the metallic sample to be analyzed in a current of oxygen so as to generate a gas and comprising a single non-dispersive infrared analyzer having a single detector means for detecting both carbon monoxide and carbon dioxide, said single detector means exhibiting substantially the same sensitivity to both carbon monoxide and carbon dioxide in said gas generated in said furnace.

2. An apparatus as in claim 1, wherein said analyzer comprises:

first and second light sources;

first and second gas filters respectively arranged adjacent said first and second light sources;

a chopper means operatively arranged to intermittently interupt light rays emanating from said first and second light sources through said first and second gas filters;

a comparison cell arranged adjacent said chopper means to receive light emanating from said first light source and passing through said first gas filter and said chopper means;

a sample cell arranged adjacent said chopper means to receive light emanating from said second light source and passing through said second gas filter and said chopper means;

first and second filter means respectively arranged adjacent said comparison cell and sample cell to selectively remove bands of infrared radiation;

a detector means for detecting infrared rays corresponding to a particular band of infrared frequencies.