Keywords: Beckman patent 1071952 Sheet 1 crop.tif en Patent 1071952 sheet 1 showing diagrams for the Recording apparatus for recording gas concentrations in the atmosphere Patent granted October 7 1952 for the patent application filed February 18 1946 1952-10-07 Institution Chemical Heritage Foundation object history exhibition history credit line CHF Collections http //www chemheritage org/ Chemical Heritage Foundation accession number Image downloaded with permission from the Chemical Heritage Foundation as part of the Wikipedian in Residence initiative accession number http //www chemheritage org/ Chemical Heritage Foundation CHF-cooperation PD-USGov Patent drawings Images from US patents |