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Ionization Chambers AEC Sensor (VacuTec, Germany)
Ionization Chambers for Automatic X-Ray Exposure Control
|Energy range / tube voltage||(40 ... 150) kV|
|Dose rate range||(0,5 ... 1000) µGy/s|
|Exposure dose range1)||(1 ... 100) µGy|
|Digital resolution (selectable)||0,025 µGy|
|Eposure time range1)||1 ms ... 10 s|
between sensor fields
|Attenuation factor1)||< 1,04|
|Aluminium equivalent||< 0,75 mm Al|
|Supply voltage (positive and negative)||±(11,5 ... 16)V DC|
|Digital output||Differential signal (RS 422), pulse width 2 µs|
|Ramp output (with ramp module)||0 ... 10 V|
According to DIN 6815 dose measurement
is carried out as follows: the air kerma (in Gy)
is measured immediately downstream of the
combined scattered-ray grid/measuring
chamber using a radiation quality attained
at a high-voltage of (70...80) kV and an Al
attenuation layer thickness of 25 mm.
|For detailed technical information |
please require our documents.
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Ionization Chambers AEC Sensor (VacuTec)
The ionization chambers are used as sensor elements for automatic X-ray exposure control units.
They are comprised of air-filled parallel chambers with 1, 3 or 5 measuring fields, coupled with an amplifier and a field selector.
The low overall thickness of 6 mm ensures the chamber may be used with all modern X-ray equipment.
Principle of Operation
The current generated in the sensor fields by the X-rays will be amplified, digitized and fed to the Automatic Exposure Controller.
The AEC supplies the cut-off signal to the generator, and thereby ensures an optimal and reproducible image quality, independent of the radiation quality, object density and other factors.
The ionization chambers are supplied with minimized chamber electronics, that amplify, digitize and process the generated current according to the field selection.
The electronics also generate the chamber voltage without the need for an external high-voltage source.
In order to assure the backward compatibility with conventional interfaces a separate ramp module converts the pulses into a voltage ramp.
This ramp module should be placed between the interface cable and the AEC interface on the generator site.
The listed sizes of AEC chambers are supplied as a standard, but other dimensions are available on request.
The minimized chamber electronics are mounted directly on the side of the chamber. If necessary there are versions with electronics separated up to 90 cm distance from the ionization chamber.
|Type||Description||Size L2xB2 (mm)|
|139 00 03||5-field chamber with|
|450 x 470|
|141 00 18||3-field chamber with electronics||374 x 374|
|142 00 13||1-field chamber with electronics||374 x 374|
|145 00 44||3-field chamber with electronics||450 x 450|
|147 00 05||3-field chamber with electronics||370 x 450|
|151 00 21ì||3-field chamber with electronics||450 x 470|
The series AEC-Sensor digital has been optimised for latest flat-panel detectors.
Chambers almost invisible measuring fields are a result of an innovative construction, which yields an extremely homogeneous X-ray absorption of the measuring chamber for all relevant tube-voltages in medical X-ray diagnostics.
Chambers thickness of 6 mm, flexibility in size and the specifications correspond to the conventional ionization chambers.