anna yielé thernevuelear deviees detonated st Bikini Atell. In omer that oe true measure could be made of initial game refiation, a requirennt ef the measurenents was to enable separation ef initial from resiéul guma reiiation. Measurements of the residual game exposure rate and decay rate were required at know times fer stations instrumented fn so contaminated field, anf efter all shots, te allow extrapolation of resiéual exposure measurexents to tines other than recovery time. For those stations et which snitial gums Gata were recorded, residmal-field gaume exposure rate measurements were required to allow for correction of the initial date te account for the effecg of the residual garma field. The initial exposure values, after correction for betatron ealibititon end shielding effects, are accurate to within 3 percent, iacluhing errors @ue to calibration, reafout, directional response of the film, and processing. Gris aceurecy percentage 1s based on previous experience. ta indivifusl cases where the residual game econtaxrination was properticnately larger, the accuracy nay be reduced, particularly ia those cases where the residue) ganm contamination was estimated. discussed infividually as they appear. These cases are The photograghic and quarts-fiber dosineter reafings are generally recommended as being most reliable on a etetistical basis, since thay were put out in large minbers and in may ranges. at each station location. Statistical variation for these infivi- dual detectors was vithin 10 percent. ST, Loum US The residual exposure values, after eorrection for shielding effects and energy response, should be accurate to within 5 percent. Tis m>