Acta Facultatis Ecologiae - Technická univerzita vo Zvolene

144AG - radon activity concentration [Bq.m -3 ]12010080604020y = 0.92x + 7.4R 2 = 0.9400 20 40 60 80 100SCH 1L - radon activity concentration [Bq.m -3 ]120Fig. 5 Correlation plot of the 222 Rn activity concentration measured by one liter scintillation chamberand AlphaGUARD monitorAG - radon activity concentration [Bq.m -3 ]12010080604020y = 1.01x + 7.58R 2 = 0.9500 20 40 60 80 100LSCH - radon activity concentration [Bq.m -3 ]120Fig. 6 Correlation plot of the 222 Rn activity concentration measured by a large scintillation chamberand AlphaGUARD monitorThe figures 4, 5 and 6 show the correlationplot of radon concentrations measured by one literscintillation chamber and the large scintillationchamber, one liter scintillation chamber and AlphaGUARDmonitor, and the large scintillationchamber and AlphaGUARD monitor, respectively.The relations between radon activity concentrationsmeasured different radon monitors are linearand the correlation coefficients are very high(R 2 ~ 0.95). However, as can be seen in Fig. 5and 6, AlphaGUARD records radon activity concentrationsa few percent higher than the other twomonitors. It is caused mainly by the difference inthe measurement of daily variations where Alpha-GUARD provides higher values of radon activityconcentrations in their minima than scintillationchambers (Fig. 7).