10 LOCKHART AND PATTERSON RADON CONCENTRATION (pCi/m3) 300 © ASSUMES SECULAR EQUILIBRIUM OF RADON SERIES CORRECTED FOR NONEQUILIBRIUM OF SERIES 200h- (WITH COLLECTION TIME AND STANDARD ERROR INDICATED) 100}- & oO mB 08 Orr f ogl_l te 0700 an b--- ~=-5 0800 L MEASURED p VALUES Bm Ge . l 0900 é -7 1000 1200 1300 i400 Moo JANUARY 5, 1I965-EASTERN STANDARD TIME Lec Tt _ 1500 1600 Fig. 9 — Atmospheric radon concentrations on January 5, 1965 m. 300f> S ~ S & 200}- -& Go a ‘. ‘Sy . ae x ASSUMES SECULAR EQUILIBRIUM OF RADON SERIE S CORRECTED FOR NON-EQUILIBRIUM OF SERIES (WITH COLLECTION TIME AND STANDARD ERROR INDICATED) ~ b z ~~ ~~ iad 8 y Z ~ ~~ = 7 ao > 100 ;— a at ox ° MEASURED » VALUES OB * o7lk O6 ne eee ' $----$TT Fe ? ae TTT 0800 | 0900 } 1000 al 1100 1 1200 l 1300 l 1400 JANUARY 7, (965- EASTERN STANDARD TIME ! 1500 i 1600 ia paren ae eee Fig. 10 — Atmospheric radon concentrations on January 7, 1965 vs encountered during the experiment. Account has been taken of the changes in p with time during the collections as described in the Appendix (this was ignored in the general solution of the experi- 7 me ariseRtge ats eg ae apne oRTag mental procedure), the changing composition rns enrsian caused by withdrawal of samples, and the backgroundof other airborne radioactivity. The agree- mentis entirely satisfactory in view of the difhiculty ae ~~ a in setung an exact zero time for introduction of the radon, which was degassed from a radium solution, and the impossibility of evaluating the affect of the chamber walls both in removing aerosols and in removing radioactive atoms or ions. This wall effect could result in the lower p values observed and in the lack of closer approachment to the 0.735 equiltbrium value. The lack of quantitative agreement between the measured radon concentrations and the added quantity of radon was rather disturbing. Studies currently underway, however, show that there is a decided wall effect and that the chamber surfaces are in competition with the aerosol for attachment of the radioactive atoms or ions of the radon decay products and that, in the absence