Exradin A28 Ion Chamber

Exradin A28 Ion Chamber

Deprecated: implode(): Passing glue string after array is deprecated. Swap the parameters in /home/clients/844ee2187cee70a16a19090345f717c4/web/medical-physics/plugins/content/jw_allvideos/jw_allvideos.php on line 73

For relative dosimetry scanning and measuring points in water, air, or other phantom material



The Model A18 Chamber features exceptional spatial resolution for relative dosimetry scanning, and is capable of measuring small field sizes of 6.9 mm by 8.3 mm for accurate point dose measurements.



Its waterproof construction makes it ideal for use in water phantoms. The chamber vents through a flexible tube that surrounds the triaxial cable, ensuring the collecting volume is in pressure equilibrium with the surroundings. The design assures there are no stem or voltage soakage effects, providing precise and reliable measurements.



The Model A18 is constructed of rugged C552 Shonka air-equivalent plastic, providing excellent conductivity and years of reliable use.



  • Proven guard design yields stable, precise measurements and minimizes settling time by creating uniform field lines
  • Shell, collector, and guard are all made of durable, long lasting Shonka conductive plastic
  • Use of homogeneous material throughout the chamber minimizes perturbation of the beam due to the presence of the chamber and optimizes measurements
  • Axially symmetric design of the chamber provides an uniform, isotropic response
  • Inherent waterproof construction eliminates need for additional protective coverings
  • Non-removable one piece stem for easy, precise positioning
  • A matching 2.0 mm thick Cobalt-60 build-up cap of C552 Shonka air-equivalent plastic is provided for air calibrations and measurements
  • Ionization collection efficiency is always 99.9% or better
  • Collecting volume is 0.125 cc


REF Number 92729
Collecting Volume 0.125 cm3
Nominal Calibration Factor 25 R/nC
Centroid of Collecting Volume 4.9 mm from tip of chamber
Collector Diameter 1.0 mm
Outside Diameter of Shell Collecting Volume 6.9 mm
Wall Thickness 1.0 mm
Shell, Collector, and Guard Material Shonka air-equivalent plastic C552
Included 60Co Buildup Cap Wall thickness of 2.0 mm; contructed of C552
Venting Vented to the ambient via the flexible vent tube surrounding the triaxial cable
Stem Non-removable 0.69 cm OD x 5.5 cm long, black anodized aluminum
Nominal Collection Efficiency 1.000
Maximum Polarizing Potential 1000 V
Nominal Inherent Leakage Currents 10-15 A
Low-Noise Triaxial Cable 50 ohms, 29 pF/ft, 1.5 m long
Signal Connector Triaxial BNC plug (2-Lug, male pin); others available upon request
High Voltage Connector Integral with triaxial connector (shell of chamber is common with connector body)
Waterproof Yes
Product Standards CE0413, Designed to meet IEC 60601-1, IEC 60731