Downloaded from https://www.everyspec.com I AMCP 706IN 2. The subset of these that must be used TABLE 11-1 in testing TYPICAL ENVIRONMENTAL FACTORS' 3. The capability for generating and con- trolling them. Acceleration Meteoroids Acousti= Moisture The environmental factors that can affect Aerodynamic heating Nuclear radiation Th eviometa acor ha cnAilbdo Pollution, air - the behavior of the item during field oper- Asteroids Pressure, air ations must be determined, These factors Clouds Rain must be simulated to the extent feasible Cosmic radiation RF Interference within the constraints of cost, schedule, and Dew Salt so-ay testing capability.
Not all environmental con- Electric atmosphere Sand and dust ditiols that affect behavior can be readily Explosive atmosphere Shook, mechanical simulated, and very rarely can all be gener- Fog Sleet ated simultaneously to account for inter- Frost Snow action effects, Trade-off; therefore must be Fungi Solar radiation made when selecting the test condition. Oaoss, dissoclated Temperature Oasse, Ionized Thermal shock Ref. 5 is the definitive AMC treatise on Georiagnetism Turbulene the environment. This chapter is a brief Gravity Vacuum Hail Vapor trails summary of a few of the more important Humidity Vibration points.
Wle Winds and gusts Insects Wind shear 6-2 ENVIRONMENTAL FACTORS AND Magnetic fields Zero gravity THEIR EFFECTS Environmental conditions may be, for severity levels, It is posbmble to select repre. example, weather and solar radiation, or sentative characteristics, such as averages or mechanical shock during transportation and maximum levels, of major factors wlich haddling, air conditioned rooms for com- adeq' itely describe conditions for a test. ,uteri, and radio frequency Interference, Table 6-1 Hsts some environmental factors Environmental conditions of greatest for a typical system.
interest from the reliability viewpoint are those that have detrimental effects on equip- The mat enonvirsonmental t.lindetionm i that ment operation, Table 6-2 lists typical det- an item encounters during its lifetime is Its rimental effects of environmental factors. environmental profile, Therefore, environ- In many cases, effects not detectable when mental testing must consider all the environ- the factors atэ encountered singly appear ments encountered in manufacturing, stor- when two or more are present simultaneous- age, transportation, and handling, as well as ly. For example, some electronic compo- those experienced during operational use.
nents function properly in either a low tem- perature or a vibrational ervironment, but The environmental conditions are not when the environments are,,combined, com-r always known in explicit form. No one ponent leads break. Some poseible corn- knows precisely, for example, the environ- bined effects of several environmental mental profile that a field artillery rocket factors are illustrated in Table 6-3. Corn- will experience throughout its life including bined environments do not always have all types of environmental factors and their adverse effects, For example, low temper-