Our History

In 1922, twenty-seven years after Röntgen had discovered X-rays, Professor Hammer from the Physics Institute of Freiburg University founded PTW to produce and market his development of an X-ray dosemeter based on electrostatic relay, a revolutionary new electromechanical component for measuring very small electrical charges.

In 1927, Dr. Herbert Pychlau took over the company and developed it during four decades into an internationally recognized manufacturer of quality dosemeters for medical radiology. During the second half of the 20th century, the business grew into an acknowledged international company, acquiring a good reputation as a pioneer with both scientists and users.

Technical improvements from electrometer tubes and transistors to microprocessor control and computer communication modernized the growing spectrum of products. Increasing exports finally led to a further milestone in the company's history: the foundation of PTW-New York as the first PTW subsidiary to distribute and service PTW products all over the American continent.
Further PTW subsidiaries all over the world have followed.

PTW subsidiaries at a glance:

  • PTW New York (founded in 1995)
  • PTW-France (founded in 2002)
  • PTW-Asia Pacific (founded in 2004)
  • PTW-Latin America (founded in 2005)
  • PTW-Beijing (founded in 2007)
  • PTW-UK (founded in 2008)
  • PTW Dosimetry India (founded in 2011)
  • PTW Dosimetría Iberia (founded in 2012)

PTW-Freiburg's production area, which in the very beginning was located in Professor Hammer's garden shed, covers a total area of 6000 m² today. PTW employs a staff of 270 associates all over the world. The company, which scores steady growth, is the recognized market leader in dosimetry today.

PTW Innovation Milestones >>


We at PTW constantly strive to be competent and reliable partners for our customers all over the world, which includes maintaining demanding quality standards as well as comprehensive service and support standards. We will continue our efforts to develop the most reliable and top quality dosimetry products in the future as we did in the past, products in which users and patients put their trust.

Because we know what responsibility means.
Knowing what responsibility means.

More than 90 years of product and service excellence in dosimetry - from the first dosemeter in 1922 to the largest range of high-tech solutions for any dosimetry need. That is what PTW stands for.