3.6 ION-EXCHANGE COLUMNS Ion-exchange columns were placed at someofthe stations to test their suitability as collecting devices. They consisted of a lucite columnfilled with Dowex-50 or Amberlite XE-81 (now designated as Amberlite MB-1), a funnel, and a polyethylene bottle to collect the effluent (Fig. 3.6). It was hoped that the use of these columns would preserve the contaminantin its original state and allow the components to be investigated by elution with different reagents. 3.7 GUM-PAPER COLLECTOR This collector consisted of a 2-ft square of Kum-Kleen gummed paper mounted on cardboard. Ten days’ supply of this paper was shipped to each collecting station, where the operator had only to remove the protective cover and expose the gummed surface to the fall-out. Exposures were changed either at 12- or 24-hr intervals over a period of 5 to 10 days. These units were primarily designed to collect fall-out at great distances from the shot island and were sent to various a@fgfiboring atolls as well as installed on certain task force ships (Fig. 3.7). we? , 3.8 AIR SAMPLER An air sampler was installed on the island of Nancy. This unit consisted of a motor-driven filter-paper belt and a blower having a capacity of 4 cu ft/min. It was designed to trigger at shot time and record total activity with time over a 1-hr period. 3.9 DESIGN OF STATIONS There were three basic types of stations: land, lagoon, and sea stations. In addition there were stations aboard task force ships and at neighboring atolls. The land stations on Eniwetok Atoll islands consisted of a concrete shield and platform so placed that the collecting instruments were protected from blast and thermal effects (Fig. 3.8). ihe, The thickness of the shield varied with the distance from the blast. The concrete platform was equipped with studs for mounting the instruments, At these stations the following instruments were used: total collector, differential fall-out collector, incremental collector, two rain gages, and an ion-exchange collector. The rain gages had different recording rates. Those instruments which had to be started at shot time were started by a trigger actuated by light from the bomb. The lagoon stations were modified Navy 60-man life floats. A deck was built over the top of the float, and a breakwater, which consisted of a cross-hatched wooden planking, was installed beneath it. A gimbal mount wasinstalled on the life float to hold a rain gage, and a 0.375-in. steel shield was installed around the rain gage to protect it from blast damage. This gimbal mount had a submerged vane to damp the oscillations created by the waves. In addition to the rain gage, the floats were equipped with an incremental collector, differential fall-out collector, total collector, and trigger mechanism (Fig. 3.9). The sea stations were free-floating standard Navy type 3 Dan buoys (Fig. 3.10). They were equipped with a total collector and a 1-ft square of Kum-Kieen gummed paper mounted on the corner reflector. sa 25