Sparking potential

Table 8. Sparking Potential for Small Wire Concentric in a Round Tube...

Figure 6. Sparking potential in air as a function of pd, the product of pressure and gap spacing. (Adapted from data of Cobine, 1958.)...

TABLE 17-13 Sparking Potentials (Small Wire Concentric in Pipe)... 

Ignites in air above 288°C when exposed to spark. Potentially explosive reaction with aluminum chloride -I- bis(2-methoxyethyl) ether. Reacts with ruthenium salts to form a solid product which explodes when touched or on contact with water. Reacts to form dangerously explosive hydrogen gas on contact with alkali, water and other protic solvents (e.g., methanol, ethanol, ethylene glycol, phenol), aluminum chloride -I- bis(2-methoxyethyl)ether. Reacts violently with... 

The value of dS/dE was considered. If the applied voltage changes by E, the whole discharge space must reach the sparking potential once. Accordingly, the discharge also occurs once. Hence, dS/dE = S/E is obtained, where S is the total discharge area. 

The threshold voltage for gap breakdown is governed by Paschen s law [12], which states that in a given medium the sparking potential is a function of the product of the density of the medium and the distance between the electrodes. The critically sized gap varies, therefore, with the applied voltage, and there is a minimum voltage below which a spark will not pass between two electrodes, e.g.. in air the voltage is about 300 V. 

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