After the production of gas and water meters, the BKS started in the beginning of the 20th century with the production of electricity meters. To be on top of the development Felix Ketterer asked the clock maker school of Furtwangen to instruct his oldest son Oskar in manufacturing electricity meters. In the year 1900 the first alternate current meters left the company. In the beginning of 1920 the new production branch was formed. The German Meter Company DZG.
The year 1910 was in every respect the most successful one. It was going to be also the last one with Felix Ketterer as the leader of the company. He died in 1911, 64 years old. Benedikt Ketterer & Sons had grown to be the greatest company in Furtwangen. More than 350 employees were engaged in the company. After Felix Ketterers death, Oskar Ketterer took over the guidance of the company together with his brother in law, Ernst Hepting.
With the 1920´s came the possibilities to electrify the clock factories of Furtwangen through radio engineering. They expected a new future trade. Together with Prof. Dr. Weiss, the BKS developed plans for radio construction inclusive pieces which could be done as radio self service. The radio pioneer of Furtwangen, Oskar Ketterer had the fully support of his brother in law, Emil Ketterer the leader of the clock maker school. He acted as consultant of the technical domain. The market worked out very fast. But the BKS stayed with its main business, the production of gearings.