Development of Instrumental Techniques: The Twentieth Century - Important Figures of Analytical Chemistry from Germany in Brief Biographies - page 115

Fig. 4.16 Portrait of Werner
Fischer (1902-2001). Photo
Fresenius Z. Anal. Chem. 190
(1962) 1, with permission
the institute and soon continued his research on rare earth separations by solvent
extraction and started in new fields, the fundamentals of chromatography and
determination of rare elements [ 97 ].
Erwin L ehrer (born 5 July 1904, Reutlingen, died 10 October 1997)
After high school in Reutlingen, he studied physics in Tübingen and com-
pleted his PhD there in 1926 and worked as assistant. In 1927, he joined the I . G .
Farbenindustrie AG , Werk Oppau [now Badische Anilin - und Sodafabrik ( BASF )
Ludwigshafen ]. He pioneered the development of analytical recording instru-
ments for chemical processes including data treatment (for portrait see Fig. 4.17 ).
Initially, he worked on ferromagnetism [ 98 ] before he developed a sensitive
bolometer detector for infrared (IR) radiation [ 99 ]. In 1936, he introduced a light
chopper to the design of the IR spectrometer [ 100 ] and in 1939 the double-beam
technique, resulting in the construction of the first fully automated IR double-
beam spectrometer [ 101 ]. This instrument marks the beginning of systematic spec-
tral analysis, i.e. structural and constitutional analysis [ 102 ]. After World War II,
this instrument was confiscated by British forces and shipped to the UK, where it
disappeared. The double-beam design became standard for all optical spectrom-
eters until the advent of Fourier transform instruments.
The first design of automated IR double-beam spectrometer was not sufficiently
rugged for online continuous process analysis. For this reason, Erwin Lehrer
together with Karl Friedrich Luft developed in 1938 a non-dispersive instrument