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.
|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)|
|Product Standards||CE0413, Designed to meet IEC 60601-1, IEC 60731|
Model 12s Schematic
Specifications subject to change without notice.