Features
- Shadow-free design for use with automatic exposure control
- Sensitive volume 6 cm3, vented to air
- Suitable for measurements in front of and behind a phantom
The 34069 SFD mammo chamber is a high precision chamber for measurements in diagnostic radiology at high dose rates and in mammography. 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 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.
Specifications
| Type of product | vented plane parallel ionization chamber acc. IEC 61674 |
|---|---|
| Application |
absolute dosimetry in diagnostic radiology |
| Measuring quantities | air kerma, exposure |
| Reference radiation quality |
30 kV, HVL 0.337 mm Al (RQR-M3) 70 kV, HVL 2.58 mm Al (RQR5) |
| Nominal sensitive volume | 6 cm3 |
| Design | not waterproof, vented |
| Reference point | in chamber center |
| Direction of incidence | perpendicular to chamber plane, see label ‘Focus’ |
| Nominal response |
230 nC/Gy |
| Long-term stability | ≤ 1 % per year |
| Chamber voltage | 200 V nominal ± 400 V maximal |
| Polarity effect at RQR-M3 (RQA-M3) | ≤ 1 % (≤ 2 %) |
| Directional response in water | ≤ 3 % for chamber tilting up to ≤ ± 15° |
| Leakage current | ≤ 5 fA |
| Cable leakage | ≤ 1 pC/(Gy·cm) |
Materials and measures
| Entrance window |
0.32 mm PMMA, 1.19 g/cm3 0.002 mm graphite 0.32 g/cm3 |
|---|---|
| Total window area density | 38 mg/cm2 |
| Water-equivalent window thickness | 0.4 mm |
| Sensitive volume |
radius 15.2 mm depth 2 x 4.21mm |
Ion collection efficiency at nominal voltage
| Ion collection time | 550 µs |
|---|---|
| Max. dose rate for ≥ 99 % saturation ≥ 95 % saturation |
0.53 Gy/s |
Useful Ranges
| Chamber voltage | ± (100 … 400) V |
|---|---|
| Radiation quality |
(25 … 150) kV X-rays |
| Field size | (5 x 5) cm2 … (40 x 40) cm2 |
| Temperature | (10 … 40) °C (50 … 104) °F |
| Humidity | (10 … 80) %, max 20 g/m3 |
| Air pressure | (700 … 1060) hPa |
Parts
TN34069-2,5 SFD mammo chamber 6 cm3, connecting system BNT
TW34069-2,5 SFD mammo chamber 6 cm3, connecting system TNC
TM34069-2,5 SFD mammo chamber 6 cm3, connecting system M
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