gummed paper mcuntead on water resistant cardboard. In both methods, the collectors were continuously exposed from the time of their place~ ment wtil recovery. Samples obtained were used primarily in deter- mining the final fallout distribution patterns. 31.2 Differential Fallout Collector The differential fallout collector (Fig. 3.2), employed to collect fallout as a function of time was an improved version of the belt sampler used during IVY. It was employed on most land and many lagoon stations. It was designed to expose 40 jars consecutively at 5 min intervals after being started oy a signal from a light-activated trigger. This equipment was powered by a 6-v, 110—amp-hr storage battery. 301.3 Badge Use was made of the Nation.l Bureau of Standards film badge pack to measure the integrated gamma radiation dose at each stetion where fallout was collected, These dosimeters were provided amd procossed by Project 2.1 personnel. ‘A Zeled Gamma Time-Intensity Recorder The gemma tine-intensity recorder was used in conjunction with a data recuction system, to provide long-term, continuous information relative to radiation fields, it consisted of a series of ionization chambers, associated electrometer cand relay circuitry, and tsterlineAngus pen recorders 2</ The information for euch chanber was stored us & simple pulse, euch of which corresp:nded tc the basic increment of gama radiuticn for the siven chamber, The system was essentially of the churge integrating autorecycle type, the chember being rechar;ea to its original voltaze as each basic increment of radiution was received and recorded. The basic chamber increments were 0.1 mr, 10 mr, 1 r, and 100 r covering the range from 0.1 mr/hr to 10,000 r/hr. The instrument was powered by ten 150-amp-hr betteries, eight of which were in series providin,, 48 v for the relay circuits and power to drive the pens in the esterline-angus recorder; the other two were in purallel proviaing 6 v for the filemente of the anvlifier tubes in the detector heaus, A spring-driven mechanism moved the paper in the isterline-Angus recorders. 3.1.5 Prototype Collecting Devices Severul protetype instruments were tested for their possibilities as fallout ind bare surge sumplers., Two such instruments vere the electrostetic precipitatcr cond the automatic water drop collector. ‘The samples collected by those instruments wero analyzed at the LENVL, The results are given elsewhere ,18/ The electrost:tic precipitator was developed cs a fo; sampling device to obtain information on size, radioactivity, snd ionic content of individual liguid sercsol purticles., The serpling was uccomplished 37