Preliminary Study of Dial Reading Performance During Sustained Acceleration and Vibration

Résumé du livre

Booster induced spacecraft vibrations occur in combination with booster induced sustained acceleration. This was a joint NASA-AF study to provide a preliminary cursory evaluation of the effects of this environment on crewmen. Six subjects were used in 60 tests to measure the decrement in dial reading ability as a function of the level of 11 cps gx vibration and the size of the dial, where a bias acceleration of 3.85 Gx was superimposed on the vibration. Dial reading errors were inversely related to the arc length of the interval between dials and directly related to the amplitude of vibration. There was approximately 50% distortion of the 11 cps vibration acceleration, which markedly influences the interpretation of results and their comparison to measurements of visual decrements from 11 cps vibrations with 1Gx bias loads. In most general terms, however, the 3.85Gx bias, and/or the unidirectional force (i.e., the resultant acceleration was always greater than 0 G) creates a subjectively more tolerable environment than with a 1 G bias. Vibrations of 3.85Gx plus or minus3. Ogx were without serious subjective effects in exposures of 90 seconds duration. Gross comparisons of dial reading performance under the two conditions provide some indication that the greater bias acceleration is associated with less visual decrement.