Can Different Electrodes Affect Air's Dielectric Strength Values?

[Physicist3]

Hi,

Am I correct in thinking that for a medium such as air, the dielectric strength is a property of the material and as such has a single value for that material? The reason I ask is because I have been testing the breakdown of air between different types of electrodes and because the breakdown is different for different electrode heads, I will end up with multiple values of dielectric strength (kV/mm). Is this possible?

 

[zoki85]

Hi,

Am I correct in thinking that for a medium such as air, the dielectric strength is a property of the material and as such has a single value for that material? The reason I ask is because I have been testing the breakdown of air between different types of electrodes and because the breakdown is different for different electrode heads, I will end up with multiple values of dielectric strength (kV/mm). Is this possible?

1. Yes, but even for uniform E-fields it is also a function of pressure and temperature.
2. Yes, it is possible becouse for different types of electrode heads the field configuration in the gap isn't same

 

[Physicist3]

So if all three electrode types were tested in the same location (same pressure and temp), the difference in breakdown voltages observed would be because of the distribution of the electric field which differs with each electrode type?

 

[zoki85]

Yup