retained the snap-bag gas-sampling devices used in IVY. The B-36s we Fitted with a filter installed in the cabin pressure system and each rp- ceived both a double-squeegee gas-sampling system and a particulatesampling device. One of these B-36s was equipped with an array of ele tronics to serve as backup to the primary B-36 controller, which, likel the F-84Gs, was also used in IVY (Reference 29, pp. 97-98). were equipped to perform "heavy nuclide" sampling. The WB-29 air The WB-29s carried "shoe box" in each wing; each box had two filter panels but the aircra had no special instrumentation, controls, or sampling indicators. The only proof of sample collection while airborne was the aircraft backgrpund as measured by a T1-B radiac meter (Reference 29, Chapter 8, et seq). The double-squeegee was designed for operation at altitudes of 36, to 50,000 feet (10.97 to 15.24 km). ‘Two air-cooled, four-stage radial pressors, operated electrically, exhausted a portion of the jet engine take air into a 500-in- (8,193-cm>) collection vessel at 3,000 Lb/in? (211 kg/om-). Each compressor was rated at 1,728 in?/min (28,317 on? / i Both compressors operated in parallel, pumping into a single collectio vessel. There were two versions of the double-squeegee that differed with respect to filtering the compressor input air. A "special" doubl squeegee was used on three F-84Gs, which contained a special filter in gral to the sampling system. The other seven F-84G systems used the f in the cabin pressurization system (Reference 29, Chapter 8 et seq). passing through the filter was not used for breathing during cloud sam operations; TG 7.4 policy required sampler aircraft personnel to breat 100-percent oxygen from the time of cloud entry to mission completion Enewetak.) Table 12 summarizes the sampling systems installed on the F-84Gs. The RB-36 that served as the airborne sampler controller was No. 1 (radio call sign Cassidy). The radio compartment contained two ART-13 transceivers; one operated in the range of 3.3 to 18.1 MHz, the other 200 to 600 kHz. The TG 7.4 Technical Advisor rode in this compartment had selection switches enabling monitoring or communication with sampldr 136