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USER MANUAL
12
TECHNICAL DATA
Basic functions
AlphaGUARD D50
Type of radon detector
Ionization chamber, HV
|
750 VDC
Mode of operation
3D-alpha spectroscopy and current mode
Total detector volume
0,62 liter (38 cubic inches)
Active detector volume
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
Detector efficiency
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
1 Bq/m³ (0.01 pCi/l)
Fold back protection
> 10.000.000 Bq/m³ (> 300 000 pCi/l) verified
System linearity error
< 3% within total range
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
