several promising features, one of which is its adaptation for collecting dry particles, The rechanical parts are entirely enclosed. It is powered by compressed gas which makes a compact source that is easily recharged and largely unaffected by atmospheric conditions. This device needs further engineerin, development. It will be field tested agein at future operations. 3.2.7 Electrostatic Precipitator This device for collecting smell aerosol droplets vas the most complicated sampling anparatus used on Project 2.5a. Its large pover requirements were sup lied by a motor-generztor set. It was almost impossible to keep this equipment in operating condition, purticularly after the fire cauced by Shot 1 which dectroyed all the spare parts for the electrostutic precipitator. Definite evaluation of the usefulness of the electrest:tic precipitator .. collecting aerosols at nuclear tests cannot be nade at this time. 3.2.8 Trigger veviges The light trig,er was a modification of the one used at IVY. On Shot 1, of 14 triggers surviving the blast effects 10 worked satisfactorily. The fire destroyed all spare parts so the permanently dimaged trigsers on the capsized rafts could not be replaced or repaired. At island stations these devices operated more satisfactorily than on refts. The electronic circultry was improperly protected against atmospheric conditions. A simple blast trigser designed and constructed at the site opersted successfully at island and lagoon steutions for mezaton weapons but was not sensitive enough for low yield weapons. Further uevelopment of thic type of trigver is indicated for future field oper:tions. 3.2.9 Gamma Time-intensity Recorder This device was the seme type as those used in large numbers on the YAG's in Project 6.4. Two stations were operating before Shot i, The one on Yoke was damaged by a water wave which occurred after that shot. The station on How operated sutisfectorily throughout the operation until it was destroyed by a wave after Shot 5. It collected valuabie information concerning time and rate of arrival of fallout and its decay. The dem:zed equipment was repaired and placed on Janet in preparution for Shot Echo and later moved to Leroy. It did not record any activity after Shot 6 because no fallout arrived on thit island. A more complete evaluation of this type cf insetrumdnt will be found in the Project 6.4 final report.</