Monitor Ionization Chambers 34014, 786

Large size plane parallel transmission chambers for use as dose monitors combined with calibration facilities

Vented sensitive volume of 94 cm³ and 86 cm3
Include twin-sensitive volumes
Shadow-free transmission chambers for dose monitoring with calibration facilities

The circular plane-parallel transmission chambers are used for dose monitoring in combination with calibration benches. The sensitive volumes are designed as twin-chambers with 2.5 mm measuring depth each and a diameter of 155 mm (model 786) or 148 mm (model 34014). The chamber walls and the electrodes are made of polyimide (Pl) of 0.025 mm thickness each with graphite layer. The chambers are guarded. The external diameter of the chamber housing is 230 mm. Two holes with 6 mm threads serve for mechanical chamber fixation.

Two chamber versions are available: model 786 is used together with dosemeters having the input circuits on ground potential, and model 34014 is used together with dosemeters having the input circuits on high voltage.

Type of product	vented plane-parallel
	twin-chambers
Application	dose monitoring in calibration facilities
Measuring quantities	exposure
Design	not waterproof, vented
Nominal sensitive volume	86 cm³ (34014)
	94 cm³ (786)
Nominal response	depends on field size
Chamber voltage	400 V nominal
Energy response	≤ ± 4 % (40 keV ... 60Co)
Leakage current	≤ ± 1 pA

Materials and measures

Entrance window	3 x 0.025 mm polyimide, graphite coated
Total window area density	3 x 3.55 mg/cm2
Electrode	polyimide foil, graphite coated
Outer dimensions	diameter 230 mm

Ion collection efficiency at nominal voltage

Max. dose rate for
≥ 99.5 % saturation	8.5 Gy/s
≥ 99.0 % saturation	17 Gy/s (34014)
	18 Gy/s (786)
Max. dose per pulse for
≥ 99.5 % saturation	590 μGy
≥ 99.0 % saturation	1.19 μGy

Ranges of use

Radiation quality	(7.5 ... 420) kV X-rays
Field size	≤ 148 mm diameter (34014)
	≤ 155 mm diameter (786)
Temperature	(10 ... 40) °C
	(50 ... 104) °F
Humidity	(10 ... 80) %, max 20 g/m3
Air pressure	(700 ... 1060) hPa