Milestones in the forties
Sound never heard before
The history of DELTA begins with the establishment of the Danish Acoustical Laboratory and ELDOK (Electronics Documentation and Patents Association).
The scientific engineering publications from the Danish Academy of Technical Sciences (ATV) include results from the Danish Acoustical Laboratory (Lydteknisk Laboratorium) published in the early 1940s. Entries in the ledger from 1941 were made and balanced by hand and included everything from minor purchases to employee wages. The economy of the Danish Acoustical Laboratory was managed using this ledger for ten years. In modern times, DELTA's data area corresponds to 300 standard ledgers - per employee.
DELTA develops a Danish radio tube, so that the 20 plus Danish radio manufacturers did not have to pay the patent-fee to foreign manufacturers. The Danish tube was produced in the factory Oxytron.
The sound hammer, from 1947, was used to study how noise is propageted in buildings. The tapping machine (the "Spider", from 1943) was used for studying footsteps, i.e. to determine how the sound of footsteps is propageted in buildings.