Celebrating the life and work of Hans Christian Ørsted

The discoverer of Electomagnetism


2020 marks the 200th anniversary of the discovery of electromagnetism by Hans Christian Ørsted (14/08/1777 – 09/03/1851), the Danish physicist and chemist who found that electric currents create magnetic fields. In 1820, Ørsted (commonly spelled Oersted) published a paper detailing that a compass needle was deflected from magnetic north by the presence of an electric current. Later findings the same year showed that an electric current produces a circular magnetic field as it flows through a wire.


Acknowledging Ørsted’s pioneering work and discoveries in the field of electromagnetism, Oersted's law and the Oersted, the unit of magnetic induction (Oe) are named after him. Ørsted was awarded the Copley Medal by the Royal Society of London, and a grant of 3,000 francs by the French Academy for his work. In later years he was elected a foreign member of the Royal Swedish Academy of Sciences (1822) and a Foreign Honorary Member of the American Academy of Arts and Sciences (1849). In 1829, Ørsted founded what would become the Technical University of Denmark (DTU).


Many everyday items are only possible because of electromagnetism. Imagine a world without electric motors, microphones, loudspeakers, and transformers…and that’s just the start.


Electromagetism is – of course – also fundamental to the principles of operation for the current sense transducer. Historically, engineers have been very creative when it comes to measuring current. However, when the application requires very high accuracy – such as power analysers, MRI scanners and other medical equipment, or power supplies used in particle accelerators in large scientific research establishments such as CERN, zero-flux technology, also called ‘fluxgate’, is accepted as the best solution. This approach uses the magnetic field generated by the circulation of the current.


At Danisense, we have refined and developed ‘fluxgate’, including the use of a closed loop which balances opposing magnetic fields, so eliminating offset and linearity issues. Using this combination of techniques, it is possible to achieve extremely accurate results even in harsh environments, and our products deliver best-in-class stability and accuracy.


We are therefore proud to celebrate our fellow countryman’s achievements, and we owe Ørsted a great debt of gratitude. Danisense is indeed thankful to be standing on the shoulders of such a giant.