pt cmnal ‘Maat oon sdaastaSa tte Llows: These calibrated sclutions (i1.e., Radiochemistry Center, are available from a number of sources IAEA, Nuclear Chicago) 969 brated at HASL. 68 and the reported value is very good. id~ directly, itude he listed the agreement between HASL’s measurement HASL does not calibrate for Pb and the supplier's value is accepted. for Po-210, -he Generally, and are recali- 210 HASL does calibrate and its evaluation of the Po-210 in a Pb-210 standard is now adopted rather than the equilibrium value from the Pb-210. The results of the quality control program for the October 1969 mission are summarized in Table 3d. The standards indicate that the average accuracy of analysis is within +10% or less. The blank anal- Jara- yses indicate that the contamination introduced by normal handling ‘form= and laboratory procedure is either unmeasurable or insignificant for all the nuclides studied. The duplicate samples show that the preci- sion error Of analyses is generally less than +10% except when the counting error of the measurement becomes the major uncertainty. lal— A serious exception to this general statement on analytical preds, cision is the Pu-238 and Pu-239 results from sample 2476 which differ widely from the results of its duplicate 2458. While plutonium con- centrations and ratios from sample 2458 appear reasonable for the region of the stratosphere from which it was collected, they do not Ir - 15