Human Engineering Guide to Equipment Design |
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acuity aircraft amplitude anthropometric applied Articulation Index auditory bandwidth cathode ray tube Center chord keyboard coding color components control system critical band curve data entry decibels detection dimensions display distance dynamic earphones effect equipment error evaluation example feedback filter frequency function height human engineering identified illumination increase indicators input instructor intelligibility intensity Journal keyboard knob Kryter light listener loudspeaker luminance maintenance masked threshold masking maximum measured ment method microphone minimum mockups monaural movement noise normal octave octave band operator operator's output panel Percentiles performance personnel pilot pointer position presented pure tones range ratio recommended Report Research response scale shown in Figure signal-to-noise ratio simulator sound pressure sound pressure level space spectrum speech peaks speech signal stimulus TABLE talker target task techniques threshold tion training device values variables visual acuity visual angle vocoder WPAFB
Popular passages
Page 223 - A = Alpha N = November B = Bravo O = Oscar C = Charlie P = Papa D = Delta Q = Quebec E = Echo R = Romeo F = Foxtrot S = Sierra G = Golf T = Tango H = Hotel U = Uniform I = India V = Victor J = Juliet w = Whiskey K = Kilo X = X-ray L = Lima Y = Yankee M = Mike Z = Zulu Both bases did actually exist, so the confusion could have been real. To clarify, the caller uses the phonetic alphabet: "Robins Air Force Base. R as in Romeo." If he had meant Dobbins, he would have said, "Dobbins Air Force Base.
Page 82 - Poor (difficult to judge direction and magnitude of pointer deviation). Fair (has somewhat ambiguous relation between pointer motion and motion of setting knob). Fair (not readily monitored and has somewhat ambiguous relationship to manual-control motion). Good (generally moving scale should represent outside world, or other stable frame of reference). Fair (offers saving in panel space because only small section of scale need be exposed and illuminated, and long scale is possible).
Page 71 - However, a high training level must be maintained to make accurate identification of these compound color codes, and illumination conditions must be held constant. Color coding and color blindness. About 6% of healthy, adult males have markedly reduced sensitivity to colors. Most of these so-called color-blind people can correctly identify some colors — they merely do not see as many colors as color-sighted people do. Actually, only 0.003% of males are completely color-blind, ie, are unable to...
Page 586 - MAINTAINABILITY A characteristic of design and installation which is expressed as the probability that an item will be retained in or restored to a specified condition within a given period of time, when the maintenance is performed in accordance with prescribed procedures and resources.
Page 193 - Unsatisfactory for conferences of more than two or three people; telephone use slightly difficult; normal voice 1 to 2 ft ; raised voice 3 to 6 ft "Very noisy...
Page 64 - ... on large surfaces; pastels and light gray are recommended. For general room lighting, the designer should strive for an evenness of distribution without shadows and glare. The levels required can be determined from Table 3-3.
Page 82 - Poor (position changes not easily detected). Good (most accurate method of monitoring numerical settings, but relation between pointer motion and motion of setting knob is less direct). Poor (not readily monitored, and has ambiguous relationship to manual-control motion).
Page 56 - ... of various luminances. These are 90% thresholds. The curves show that red, green, and white are nearly equal in terms of threshold intensity for color identification. For yellow the threshold is somewhat higher because of a tendency to confuse yellow with white. 3.2.5 Target Visibility Against Patterned Backgrounds Visual detection is difficult when the target appears against a mottled or patterned background, especially when other objects in the field resemble the target in size, color, shape,...
Page 51 - But for luminances above about 10 mL., acuity for white-on-black targets drops off quickly because the white parts blur. The technical visual term for this phenomenon is irradiation. With less contrast, there is lower acuity. For example, it is harder to see black on gray than it is to see black on white. This is illustrated by the curves of Figure 3-12 (Cobb and Moss, 1928), which show some measurements made with the Landolt ring seen earlier in Figure 3-9 at three different background luminances....
Page 52 - There is no lower detectable-size limit foi spots that are brighter than their backgrounds. The eye can detect a bright spot, no matter how small it is, as long as it is bright enough. For instance the star Mira can be seen even though it subtends an angle of only 0.056 sec. Lines and squares are also visible against bright backgrounds even when they are very small. For example, against a bright sky, the normal human eye can see a wire 1° long 75% of the time, even if the wire is only 0.43 sec....