Trafag
Trafag AG is a Swiss manufacturer of pressure, temperature, and gas density sensors headquartered in Bubikon, Switzerland, with an active product line for railway vehicles.
Trafag was founded in Zürich in October 1942 by Oscar Pfrunder, initially producing transformers, before relocating to Männedorf in 1944.
The company shifted towards measurement and control technology during the 1970s and stopped transformer production in 1974. The headquarters moved to Bubikon in 2012.
Ownership and leadership
The company remains family-owned, with Robert Pfrunder as chairman of the board and a second family member holding a board seat, according to the Swiss commercial register.
Robert Pfrunder — grandson of Karl Heinrich Pfrunder, the founder’s father, who provided the company with production space in 1947 — joined in 1984 and served as CEO from 1990 until 2018. He took over from Gaston Bloch, Oscar Pfrunder’s stepson, who had run the company after the founder died in 1978. Dieter Zeisel, previously chief operating officer, has been CEO since 2018.
Products for rail applications
Trafag’s rail range covers pressure and temperature sensors for rail vehicle systems: pressure transmitters, electronic and electromechanical pressure switches, thermostats, and temperature transmitters.
Applications span braking systems, pantograph actuation, traction and gearbox cooling circuits, lubrication systems, air-conditioning, and door and fire-safety control circuits.
The railway pressure transmitters NAR 8258 and EPR 8283 are built on a thin-film-on-steel measuring principle. Both carry EN 50155 (railway electronics) and EN 45545-2 (fire protection) conformity; the NAR 8258 additionally carries EN 61373 (shock and vibration) and EN 50121-3-2 (electromagnetic compatibility).
The Picostat range of mechanical pressure switches was introduced in 1990 for shipbuilding and railway use. Its railway variant, the 9R5, carries EN 50155, EN 45545-2 and EN 61373 conformity.
Market position
Production runs at sites in Switzerland, Germany, the Czech Republic, and India, with the group’s development centre in Bubikon. Thermostat and mechanical pressure switch production was moved to the Czech plant in Tachov from 2008.
According to the company, Trafag employs more than 350 people and maintains a distribution and service network across more than 40 countries. Subsidiaries include Austria, Germany, the Czech Republic, France, the UK, India, and the US, alongside a joint venture in Poland.
In rail, Trafag sells to manufacturers of rail vehicle units and systems, including makers of brake systems.
Beyond rail, its sensors serve shipbuilding, hydraulic systems, large engines, hazardous-area (Ex) environments, and high- and medium-voltage switchgear through the gas density monitoring line.
The company operates an independent, accredited calibration laboratory in Switzerland that calibrates to ISO 17025, supporting both production quality and third-party calibration services.
