We report the existence of a region within which enhanced arcing (activation) exists for palladium and palladium/silver contacts, as a function of arc current and of exposure to organic vapors. The current range where activation exists is from ∼0.1 to ∼1.2 A, where the range of exposures (partial pressure times time) used for diethyl phthalate was from ∼10−3 to ∼10 Pa s. At very low organic exposure levels (depending upon the organic vapor and the electrode metal), arc‐duration statistics show an exponential behavior. Under moderate to high organic exposure levels, arc‐duration show a log‐normal distribution similar to that obtained under clean conditions when the arc current exceeds the minimum arc‐sustaining current. At sufficiently high currents arc‐duration statistics become independent of organic exposure. The envelope of the activated curves is predicted by the activation theory of Gray, Uhrig, and Hohnstreiter.

1.
Many papers have been published in this regard. For a general survey, the reader is referred to Chaps. 8 and 9 by H. N. Wagar in Physical Design of Electronic Systems, edited by D. Baker, (Prentice‐Hall, Englewood Cliffs, New Jersey, 1971), Vol. III.
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© 1979 American Institute of Physics.
1979
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