Helmer Hartmann Dahl (17 June 1908 – 29 March 1999) was a Norwegian electrical engineer and director of research at the Chr.
He was the son of Karl Theodor Dahl (1867–1928) and Catharine Hartmann (1880–1943), He graduated as a civil engineer from the Norwegian Institute of Technology in 1931.
Due to German raid on the intelligence station Theta he left Bergen in 1942 for exile in the United Kingdom until 1945.
[3] Here he became a part of the Technical Committee of the Norwegian High Command, together with scientists and engineers including Fredrik Møller, Svein Rosseland, Leif Tronstad and Gunnar Randers.
[4] Following the liberation of Norway, Dahl worked at the Norwegian Defence Research Establishment from 1946 to 1949, but then returned to the Chr.