Yokogawa

Founded in 1915 in Tokyo as a laboratory for electrical instruments — a branch that lives on in the company's oscilloscopes and power analysers. The centre of gravity, though, is the process industries: CENTUM, launched in 1975, was among the first distributed control systems (DCS) and today runs refineries, chemical plants and power stations where thousands of measurement points are supervised at once.

The ProSafe safety system sits alongside it. Where a PLC controls a machine, a DCS controls a whole plant — and Yokogawa is one of the handful of firms that defined the category.