Exradin Model A19, 0.62cc Farmer Type Chamber

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Exradin Model A19, 0.62cc Farmer Type Chamber.

The A19 fits existing plastic phantom cavities and build-up caps, limiting perturbation and minimizing settling time in absolute dosimetry calibration.  This chamber is characterized for TG-51 procedures.  The exterior of the classic Farmer-type chamber design assures the ion chamber will fit existing plastic phantom cavities, build-up caps, and standard cesium check sources.  The A19 maintains the high quality internal design of the Exradin A12 Ion Chamber.  The one-piece, non-removable 4.6 cm stem made of black anodized aluminum is styled after traditional Farmer-type chambers.  This ion chamber comes with matching 2.8 mm thick Cobalt-60 build-up caps of C552 Shonka air-equivalent plastic.

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

• Inherently waterproof construction for use in most water tanks - eliminating the need for waterproofing sleeves or protective coatings.

• Chamber vents through a flexible tube surrounding the triaxial cable - vent tube is sealed to the chamber body and open near the connector; ideal for use in water or plastic phantoms.

• Cobalt-60 build-up cap of matching wall plastic-type included for in-air measurements on most chambers.

Features and benefits of the Exradin Ion Chambers:

Better Components
The waterproof construction eliminates the need for sleeves or protective coatings.  Robust materials are more durable than typical chambers (i.e. PMMA thimble tips), and therefore are more suitable for routine measurements.  Excellent inherent conductivity negates the need for coatings found in other chambers, which can flake off and require careful handling.  Collector, guard and shell are made of conductive material developed by Dr. Francis Shonka, the creator of A150 tissue-equivalent, C552 air-equivalent and D400 polystyrene-equivalent plastics.

Superior Stability
The advanced guard design creates a consistent collecting volume with uniform field lines, providing a stable, repeatable signal.  Exradin detectors feature some of the quickest settling times of any manufacturer.  Exceptionally wide guard rings on all parallel plate chambers eliminate perturbation volume effects.

Ideal Design for Improved Accuracy

The Collecting volumes of Exradin Ion Chambers are defined by the guard, not an insulator, creating a significantly more stable signal than competing detectors.  Axially symmetric design ensures a uniform isotropic response and has collection efficiencies of 99.9% or greater.  Chamber vents through a flexible tube surrounding the triaxial cable is ideal for use in water or plastic phantoms.  They have homogeneous construction on most chambers.

Quick Response upon hookup

Ionization currents can be read immediately after electrometer and extension cable transients subside because Exradin Ion Chambers do not exhibit voltage soakage or stem effect.  All chambers typically have ± 10 x 10^-15 amp leakage.

Other Exradin Benefits

Exradin Ion Chambers are constructed of Shonka conductive plastics, some available in three varieties - C552, D400 or A150.  A handsome wooden case is included which protects the chambers during storage and shipment.

Specifications
Collecting Volume:  0.62 cc
Centroid of Collecting Volume - from exterior tip of shell:  13.0 mm
Outside Diameter of Shell Collecting Volume:  7.1 mm
Inside Diameter of Shell Collecting Volume:  6.1 mm
Shell Wall Thickness:  0.5 mm
Collector Diameter:  1.0 mm
Collector Length:  21.6 mm
Shell, Collector and Guard Material*:  A
Nominal Air Kerma Calibration Factor^†:  4.5E + 7 Gy/C
Recommended Polarizing Voltage:  300 V
Nominal Leakage:  ± 10 x 10^-15 amp
Maximum Polarizing Voltage:  1000 V
Waterproof:  Yes
Included Build-Up Cap:  ⁶⁰Co

* Material:  A – C552 Shonka air-equivalent plastic  P – D400 polystyrene-equivalent plastic  T – A150 Shonka tissue-equivalent plastic
† Nominal calibration factor for ⁶⁰Co at 22° C

CE₀₄₁₃, Designed to meet IEC 60601-1, IEC 60731