12 LOCKHART AND PATTERSON Tassie 6 Experimental Evaluation of 0.20 #Ci Radon Released into a Chamber of 0.31 m? Volume and Sampled at the Rate of 0.00196 m3/min* Sample Elapsed Countt Countt . Ratio (min) “ oe feu Time Count Correction Factors tera FI Corrected Count Filter ows Efficiency faa Calculated Radon Cone. (pCism’) Expected Count f111 From 100 pCifm? Radon p Corrected for p Equilibrium Assumed§ I 0-20 2390 1660 0.695 510 1.00 1.22 * 198 225 5.42 * 105 0.30 & 105 0.052 2 30-50 {0400 5360 [0.5155 510 1.00 . 5.30 x 108 1370 3.87 * 105 1.28 x 108 10.27 3 60-80 16100 7000 10.435 510 1.00 8.21 x [6 2500 3,28 x (08 1.99 « 105 (0.46 4 90-110 16900 7LO0Q 40.420) 510 1.00 8.62 x 106 2810 3.07 « 105 9.09 x 105 70.5] 5 120-140 20200 8120 10.402] 510 1.00 10.31 x 106 3230 3.19 x 105 2.50 x 105 10.58 6 150-170 19920 7920 70.398] 510 1.00 10.16 x 106 3320 3.06 x 105 2.46 x 10° 0.60 7 8 180-200 260-280 20380 21480 7980 8220 [0.392 70.383 5106 510 1.00 1.00 10.39 x 106 10.95 x LOS 3480 3730 2.99 x 105 2.94 x 105 2.52 x 105 2.65 « 105 10.62 0.67 9 284-305 16940 6600 10.390]; 510 2.00 8.64 x 106 3530 2.45 * 105 2.09 « LO 0.63 *An 0.34 (dia.) DOP aerosol was added 10 min before the start of the experiment to a concentration of 104 particies/cc; the radon addition was made during the initial 3 min of the experiment. tCorrected for counter background; a negligible background of airborne radioactivity was present. All results were normalized to the D counter as calibrated August 2, (965. Reciprocal of 0.00196 m/min. §Expected counts were obtained from Fig. 7; for the equilibrium condition this value was 4130 counts. os 08 EQUILIBRIUM VALUE Oo? Z cprun’B= * ‘a =X PERIMENTAL * @.06}° 0.5 o O7 3 06 2 qor 05 = = © O4;- o 04 3 031, mo eS u a a ao g203 Ere, a © o2b x O02 Oi 0 0 EQUILIBRIUM VALUE oO. L L 2 { 3 } 4 AGE OF RADON MIXTURE (HOURS) 5 6 Fig. |1 ~ Temporal changes in the RaC/RaB atom ratio (p} following release of 0.20 wCi of radon inio a chamber (room) of 35 m? volume. The samples were taken at 0.212 m3/min for 20 min. The background of old radon was approximately 500 pCi/m?, 0 0 ! 2 3 4 4 _t AGE OF RADON MIXTURE (HOURS) 3 Fig. 12 ~— Temporal changes in the RaC/RaB atom ratio (p) following release of 0.20 wCi of radon into a chamber of 0.31 m? volume. The samples were taken at 0.00196 m3/min for 20 min. The background ofother airborne radioactivity was negligible.