The Scripps Institution of Oceanography (Keeling) carbon dioxide analyzer at NOAA’s Mauna Loa Observatory. The analyzer (center) was installed in March 1958. It used radio tubes and collected carbon dioxide data in its original configuration until its decommissioning in January 2006. The original strip chart recorder (top) also operated from 1958 until 2006. John Chin of the Mauna Loa staff faithfully tended the analyzer from 1963 to 2004. The Observatory now maintains the instrument as a museum piece at its original location.