Downloaded from https://www.everyspec.com AMCP 700-1N TABLE 0-2 ENVIRONMENTS AND TYPICAL EFFECTS' Environment Effects Winds, gust and turbulence Applies overloads to struetures causing weakening ot col'spse; interferes with tuncUtioi such as aircraft control; convactively cools surfaces and components at low velocities and generates heat through frictiuio at high veloctles; delivers and deposits foreign materials that interfere with functions Precipitation:
sleet, snow, Applies overloads .o structures (musing weakening or collap.3e; renioues heat rain, hall, dew, frost from structures and items; aids corrosion; causas i,.ectrital failures; causes surface deterioration; and damages protective c-o•tlng. Sand and dust Finely finished surfaces are scratched and ubraded; friction between surfaces may be Increased; lubricants can be contaminated; clogging of orfices, etc.; materials may be worn, crucked, or chipped. Salt etmosphere and spray Sait combined with water is a good conductor which can lower insulation resist'qnc; causes galvanic corrosion of matals; chemical corrosion of metals is accelerated.
Humidity Penetrates porous substances and causes leakage paths between electrical conductors; causes oxidation that leads to corrosion; moisture causes swelling in materials such as gaskets; excessive loss of humidity causes embrittlernent and granulation. High temperature Parameters of resistance, Inductance, capacitance, power factor, dielectric * constant, etc., will very; Insulation may boften; moving parts may jam due to expansion; finishes may blister; devices suffer thermal aging; Sunshine Causes colors to fade; affects elasticity of certain rubber compounds and plastics; Increases temperatures within enclosures; can cause thermal aging; can cause ozone formation.
oxidation and other chemical reactions are accelerated; viscosity re- duction end evaporation of lubricants are problems; structural over- loads may oc(,ur due to physical expansions, Low templrature Plastics and rubber loise flexibility and become brittle; electrical constants vary; ice formation occurswhen moisture is present; lubricants gal end increase viscosity; high heat losses; finishes may crack; structures may be overloaded due to physical contraction. Thermal shock Materials may be over'stressed instantaneously causing cracks and mechaninal failure; electrical propertlos may be altered permanently. High pressure Structures such is containers, tanks, etc.
may be overstressed and fractured; 3 tools may look; mechanical functions may be Imlpalred. 'l