Earl E Whitamore

US Patent:

39842053, Oct 5, 1976

Filed:

Sep 10, 1975

Appl. No.:

5/611948

Inventors:

Edwin L. Karas - Sharon MA
Paul J. Lincourt - Franklin MA
John P. Callahan - Hanson MA
Earl E. Whitamore - Foxboro MA

Assignee:

The Foxboro Company - Foxboro MA

International Classification:

G01N 3112

US Classification:

23254EF

Abstract:

A flame ionization detector adapted for use in hazardous areas and for mounting in any attitude, capable of using as small a flame as can be dependably maintained because of an arrangement of the flame at the open end of a thin-walled small diameter tubular electrode inside a relatively long open ended cylindrical collector and the regulation of the rates of flows which make it possible to maximize the sensitivity of the detector to the presence of an organic vapor. Excess air is maintained at a predetermined minimum. The inside diameter of the collector is made approximately twice the visible diameter of the widest point of the flame. A curtain of air flowing at a predetermined rate through the annular passage between the electrode and collector is directed into encompassing contact with the flame and the proximity of the collector to the flame maintains a relatively dense ion bearing layer of gases at the surface of the collector. A catalytic ignitor is provided with an externally operated manual switch for cleaning the ignitor.