PTW Farmer® Ionization Chambers

Klicken um Bild zu vergrößernPTW Farmer Ionization Chambers

Thimble chambers for measuring high-energy photon and electron radiation in air or in phantom  material

  • Vented sensitive volumes of 0.6 cm3
  • Suitable as therapy chambers for use in solid phantoms
  • Flat energy response
  • A variety of different versions is available

The 0.6 cm3 PTW Farmer chambers are designed for absolute photon and electron dosimetry with therapy dosemeters. Three chamber types for measurements in air or in solid state phantom material are available:

  • Type 30010 is the standard chamber. The wall material is graphite with a protective acrylic cover, and the electrode is made of Al. The nominal photon energy range is from 30 kV to 50 MV.
  • Type 30011 with graphite wall and graphite electrode is used for therapy dosimetry, where a completely graphite-built chamber is required. The nominal photon energy range is from  140 kV to 50 MV.
  • Type 30012 is used for therapy dosimetry, where a chamber with graphite wall and Al electrode is required. The nominal photon energy range is from 60 kV to 50 MV.


The electron energy range of all chambers is from 10 MeV to 45 MeV. The chambers type 30011 and 30012 with their graphite caps are of delicate construction and should be handled with  extreme care. The guard rings of all chamber types are designed up to the measuring volume. An acrylic build-up cap for in-air measurement in 60Co beams is included with each chamber, as well as a calibration certificate.