Rugged, self-recording gauges had been developed for blast and th#rmal radiation measurements by 1954 so that complete loss of data from a pfoject would not occur if instrument recovery were delayed, for example,| by heavy fallout. For nuclear radiation measurements, however, prompt dBta recovery was still desirable because the gauges used might be thin fokls of material that would be made radioactive by the burst-time neutrons hence, early observation was necessary, before the information contaihed in the induced radiation pattern decayed away. The potential for radiation exposure of personnel responsible for] environmental measurements in general depended on their proximity to thE de- vice and the time that elapsed between detonation and instrument recovery, as was the case for weapon development experimentation: space or time to the detonation, SYSTEMS RESPONSE EXPERIMENTS. the greater the potential for exposure. To document the response of syste the hostile environment, military hardware mines) the nearer i to (such as aircraft or naval was exposed to the effects of nuclear detonations. The techniques used for ‘the systems response experiments were corgeptually simple: response. exposure of the system of interest and observation of fits Actual conduct of the experiments was far more complex. level of the threat to which the system was exposed almost always re documentation so that the response could be properly understood, nec tating an environmental experiment along with the systems response e ment. It was often not enough to know whether the system survived, rather, the response of the component parts and their interactions w required, entailing the placement of sophisticated instrumentation a recording devices. While the potential radiological exposure for these systems resp experiments was governed primarily by the closeness in space or time additional problem arose. Often, when the subject of the exposure i was recovered for closer examination, it could be contaminated by de 36