CHAPTER 3 INSTRUMENTATION The apparatus used in this operetion was designed: (1) to collect fallout samples, and (2) to measure the gamma radiation from the fallont. Various collecting devices were used to gather total fullout on a known area and increments of fallout as determined by a time or quantity basis. Also, aerosols from a known volume of air were coliected. hany of the devices were similar to thoce used in Project 5.4 at IVY; 72/ others were prototypes being field tested for the first time. sesides the fallout collectors and the devices for measuring radiation fields, accessory equipment was required vo start and stop the apparatus and to furnish power, In some cases the accessory equipment haa to meet more stringent requirements than did the primery collecting devices. A prime example was the fr-:e-floating buoy which nad to be positively identifiable by Task Force security patrols and had to be provided with a means for locating .- from a ship many miles distant, A vear of intensive investigation and testing was spent in selecting and developing e satisfactory system,* for locating the buoys. 3.1 DESCRIPTION AND OPERATION OF THE HQUIPLLNT Instrument designs were based on specific collecting requirements within the limitations imposed by certain mechanical, electrical and operational restrictions. The following sections give a brief swmery of the design and operation of the equipment. 3.1.1 Total Fallout Collectors Two methods were used to obtain samples of total fallout. A polyethylene funnel-and-bottle arrengement consisting of a 7-in. diam- eter fumiel and l-gal bottle (Fig. 3.2) was used at all stations to coltect and retein denosited material. The other collector, aiso used at all stations, consisted of a horizontal 1-ft square of transparent “Development and Testing of Identification System for Project 2.5a Free-floating Stations ut Operuticn CASTLE," Project Officer, rroj. 2,5a ltr 3-905C-4434 of 24 Nov. 1953 to STU 13. USNRDL Documert C09472 lov. 1953 (SECRET), 35