Per Vilhelm Brüel

Per Vilhelm Brüel (6 March 1915 – 2 April 2015) was a Danish physicist and engineer who pioneered and made fundamental contributions to the development of the physics of sound and vibration.

He also formed and founded the world's largest manufacturer and supplier of sound and vibration measurement equipment, systems and solutions, Brüel & Kjær.

[4] At the Technical University of Denmark, Brüel started working on his Ph.D., which today would be equivalent to Master of Science, in 1932, and finished it in about five months.

[5] In January 1939, Brüel was drafted into the Danish army to do the radio for the military for a year, and it was there he built his first instrument, a battery-operated, constant-percentage bandwidth analyzer.

In 1948, Brüel & Kjær bought their first property, a wooden army barracks in Nærum, 15 km north of Copenhagen, which are the premises where the company's headquarter is still located today.

As long as the market was limited to Denmark and Sweden, Brüel initially delivered instruments to customers on his Nimbus motorcycle.

The company eventually maintained a substantial fleet of aircraft, including two Piper Aztecs and two Beechcraft King Airs.

This made it possible for Brüel and other company pilots to make airborne deliveries directly to any customer that was located near a general aviation airport.

When Brüel was flying as PIC (pilot in command), he would often appoint a nontrained employee to be a co-pilot on some of his trips.

In the mid 80s, a number of employees were asked to get a pilot license to fly with Brüel due to concern with his advancing age.