Hermann Aron was born in 1845 and is known for his work on the watt-hour meter.
He was born in modern-day Poland and attended the high school at Kölln in 1862 and studied at the University of Berlin in 1867. He then studied at the University of Heidelberg in 1870, and received a doctorate from Berlin in 1873. He became a professor of physics at the University of Berlin and at the Prussian Army's school for artillery and engineers.
In 1883 he patented the "Pendelzähler" which was the first accurate watt-hour meter. Samuel Gardiner's earlier model only measured how long current flowed, but Aron's was able to measure in proportion to the current used. It contained two pendulum clocks and a series of dials. The meter was introduced into Great Britain by Hugo Hirst and was sold by his General Electric Company from 1888.
Aron also invented another Wattmeter, the "Aronschaltung," which measured total power in three-phase AC circuits. A business grew selling his inventions with factories in Paris, London, Vienna, and Schweidnitz, and by his death in 1913 employed over 1,000 workers. His son continued the business, mostly manufacturing radios, until it was sold in 1935 and it remained in operation until 1996.