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12 TECHNICAL DATA
Basic functions AlphaGUARD D50
Ionization chamber, HV | 750 VDC
3D-alpha spectroscopy and current mode
0,62 liter (38 cubic inches)
0,56 liter (34 cubic inches)
Type of Radon progeny filter
(detector entry window)
Fine dust filter (retention coefficient >99,9 %)
Detector filling mechanism
Design-optimized for fast passive diffusion
Transient response function
(time delay)
Signal > 30 % after 10 min
Signal > 70 % after 20 min
Signal > 90 % after 30 min
Detector signal acquisition
Fast digital signal sampling network, using
three separate ADC channels
Spectral signal extraction
DSP (Digital Signal Processing), on-line-cross
correlation algorithms
1 CPM at 20 Bq/m³ (or at 0,55 pCi/l)
Background signal due to
internal detector
contamination
< 1 Bq/m³ (0.03 pCi/l)
Measurement range Radon
(Rn-222)
2 Bq/m³ … 50 000 Bq/m³
(<0.05 pCi/l … 1 350 pCi/l)
Resolution on LCD display
> 10.000.000 Bq/m³ (> 300 000 pCi/l) verified
Instrument calibration error
(Rn-222)
r
3 % (plus uncertainty of the primary
standard)
Measurement modes and
cycles
10 min, 60 min (Diffusion)
Data capacity (non-volatile)
Up to 60 000 measurement points
~ 400 days at 10 min measuring cycle
~ 2 500 days at 60 min measuring cycle