75 cm³ SFD Diagnostic Chamber Type 34060

Shadow-free plane-parallel chamber for absolute dosimetry in diagnostic radiology

Shadow-free design for use with automatic exposure control / brightness control
Sensitive volume 75 cm³, vented
Suitable for measurements in front of and behind a phantom

The 34060 SFD diagnostic chamber is a general purpose, high precision chamber for measurements in diagnostic radiology. The chamber complies with the standard IEC 61674. Its shadow-free design makes it possible to use the chamber even while the automatic exposure control or brightness control is activated. Together with an adequate diagnostic dosemeter the chamber features a wide dynamic range for measurements either in front of or behind a patient-equivalent phantom. The length of the mounted connection cable is 2.5 m.

Type of product	75 cm
Application	absolute dosimetry in diagnostic radiology
Measuring quantities	air kerma, exposure
Reference radiation quality	70 kV, HVL 2.58 mm Al (RQR5)
Design	not waterproof, vented
Direction of incidence	perpendicular to chamber plane, see label ‘Focus’
Nominal sensitive volume	75 cm³
Nominal response	2.8 μC/Gy
Long-term stability	≤ 0.5 % per year
Chamber voltage	200 V nominal
	± 400 V maximal
Energy response	≤ ± 2 % (50 ... 150) kV
Polarity effect	≤ 1 %
Reference point	chamber center
Directional response	≤ 3 % for chamber tilting
	up to ≤ ± 15°
Leakage current	≤ ± 5 fA
Cable leakage	≤ 1 pC/(Gy·cm)

Materials and measures

Entrance window	0.6 mm polycarbonate,
	1.55 g/cm³
	0.002 mm graphite
	0.32 g/cm³
Total window area density	93 mg/cm²
Water-equivalent window thickness	0.9 mm
Sensitive volume	radius 45.7 mm
	depth 2 x 5.71 mm

Ion collection efficiency at nominal voltage

Ion collection time	1 ms
Max. dose rate for ≥ 95 % saturation	0.78 Gy/s

Ranges of use

Chamber voltage	± (100 ... 400) V
Radiation quality	(25 ... 150) kV X-rays
Field size	(11 x 11) cm² ... (40 x 40) cm²
Temperature	(10 ... 40) °C
	(50 ... 104) °F
Humidity	(10 ... 80) %, max 20 g/m³
Air pressure	(700 ... 1060) hPa