= yy . NX . ~ OS : — : a 8 Se ues “Sas =e SS aos ~~ ~ , .. = = oc as SS, =~me _ > oN ~ ~ = . s ~ s ~~ ae : re SA . . ™ - Se ~ o sno uneertainty as to the source of current fallout requires more extensive calibration than in the past. The simplicity of gummed film for daily network operation makes it necessary that it be retained for routine sampling. The possible errors in attributing activity to a given source is expscted to be overcome by a broader network of pot sampling stationse The operating and projected stations in the HASL prcgram are shown in Fig. 4. These samples will be collected monthly and analyzed for MFP and Sr-90 and probably for Cs=147e Cooperative tests will start in April 1957 on a fallout collector designed by Dre Bo Aler of Sweden. Feilout collects in a plastic funnel and is passed through a filter and ion exchange column to collect the activity. Such a collector would be simple to maintain and to ship to a central laboratory for processinge -17- oa we Saw eA want SNS . .a me >.