Acta Facultatis Ecologiae - Technická univerzita vo Zvolene

143Fig. 2 The continuous monitoring system for the 222 Rn measurement in indoor air on the basis of the largescintillation chamberdecrease on 4/4/2007 during the time interval8:00–10:00. The average value calculated fromthe radon activity concentration measured duringthe whole period is (50.7 ± 7.6) Bq·m –3 for Alpha-GUARD monitor, (47.0 ± 7.1) Bq·m –3 for one literscintillation chamber and (42.9 ± 6.4) Bq·m –3 forthe large scintillation chamber, which is a good agreementin the scope of counting errors.Indoor radon activity concentration [Bq.m -3 ]14012010080604020One liter scintillation chamberLarge scintillation chamberAlphaGUARD monitor027.III.0728.III.0729.III.0730.III.0731.III.071.IV.072.IV.073.IV.074.IV.075.IV.076.IV.077.IV.078.IV.079.IV.0710.IV.0711.IV.0712.IV.0713.IV.07DateFig. 3 222 Rn activity concentration in the room measured by three radon monitorsSCH 1L - radon activity concentration [Bq.m -3 ]12010080604020y = 0.98x + 0.7R 2 = 0.9500 20 40 60 80 100LSCH - radon activity concentration [Bq.m -3 ]120Fig. 4 Correlation plot of the 222 Rn activity concentration measured by a large scintillation chamberand by one liter scintillation chamber