Exradin A12S Ion Chamber

92725 A12S

Exradin A12S Ion Chamber


For absolute dosimetry calibrations in water, air, or other phantom material


Exradin Farmer-type Chambers are specifically designed for absolute dosimetry calibrations in water, air, or other phantom material. The Model A12S thimble chamber is a modified Farmer-Type Chamber Model A12. The collector length of the Model A12S is approximately one-third the size of the Model A12, which confines its collecting volume to more of the tip of the chamber.


Its waterproof construction and two piece removable stem 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.


Farmer-type Chambers are constructed of rugged C552 Shonka air-equivalent plastic, providing excellent conductivity and years of reliable use.


REF Number 92725
Collecting Volume 0.25 cm3
Nominal Calibration Factor 14 R/nC
Centroid of Collecting Volume 5.8 mm from tip of chamber
Collector Diameter 1.0 mm
Outside Diameter of Shell Collecting Volume 7.1 mm
Wall Thickness 0.5 mm
Shell, Collector, and Guard Material Shonka air-equivalent plastic C552
Included 60Co Buildup Cap Wall thickness of 2.8 mm; contructed of C552
Venting Vented to the ambient via the flexible vent tube surrounding the triaxial cable
Stem 1.3 cm OD black phenolic, two-piece with 5.1 and 12.7 cm segments
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

Model 12s Schematic

Specifications subject to change without notice.