= fm es 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 fallout. 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 collected. Many of the devices were similar to thoce used in Project 5.4 at IVY; 7/ cthers were prototypes being field tested for the first time. Besides the fallout collectors and the devices for measuring radiation fields, accessory equipment was required to start and stop the apparatus and to furnish power, In some cases the accessory equipment had to meet more stringent requirements than did the primery collecting devices. A prime example was the fr-e-floating buoy which had to be pesitively 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 « satisfactory system,* for locating the buoys. 3.1 DESCRIPTION AND OPERATION OF THE EQUIPAENT 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 summary 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 fumnel-and-bottle arrangement consisting of a 7-in. diam- eter funnel and l-gal bottle (Fig. 3.2) was used at all stations to coliect and retain deposited material. The other collector, also 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 at Operaticn CASTLE." Project Officez, Froj. 2.5a ltr 3~905C-4434 of 24 Nov. 1953 to 2TU 13, USNRDL Documert 009472 Nov. 1953 (SECRET), 35