Brüel & Kjær 3.13

Brüel & Kjær is a Danish multinational engineering and electronics company headquartered in Nærum, near Copenhagen. It is the world's largest manufacturer and supplier of sound and vibration measurement equipment, systems and solutions, Brüel & Kjær is a subsidiary of Spectris which has annual sales of £1.1bn and employs around 7,500 people worldwide across its four business segmentsFoundersBrüel & Kjær was founded by Per Vilhelm Brüel (b. 6 March 1915 - d. 2 April 2015) and Viggo Kjær (b. 5 June 1914 - d. 25 July 2013) on 28 November 1942. The two men met while studying at The Polytechnic School in Copenhagen (now the Technical University of Denmark). After receiving their M.S. degrees in 1939 they decided to start a company developing instruments for acoustic measurements. Holger Nielsen joined the company as third partner in 1945, and was with the company until his death in 1978.ProductsSome of the products developed over 70 years include:1940s – Precision measurement instruments including radio frequency analysers and Geiger counters.The first Brüel & Kjær instrument produced was Type 2401, a vacuum tube voltmeter. The success of the company started with Type 2301 in 1949. Since then it has been updated a number of times. The latest version, Type 2307, was introduced in 1972. In 1943 Brüel & Kjær launched Type 4301 - the world's first Charge Accelerometer, thus entering the field of vibration measurement.1950s – Sound and vibration measurements, including development of logarithmic level recorders, signal generators and frequency analyzers.1960s – Measurement microphones, preamplifiers and calibrators, along with IEC standardised precision sound level meters.1970s – Parallel analyzers, including the world’s first analyzer to use digital filters.1980s – The first commercially available instrument for sound intensity measurement, and expansions of the range of instruments; for example, dual channel FFT analyzers.1990s – Multichannel and multi-analysis systems, including acoustical holography array systems.2000s – Surface microphones and LAN-XI modular data acquisition hardware. New technologies such as TEDS, Dyn-X, REq-X.