Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx> At 04:27 PM 11/25/2005, Tesla list wrote:
Original poster: "JT Bowles" <jasotb@xxxxxxxxxxx> I have read all over the net, around 25KV/inch <<I use this one I read on one place, around 30KV/inchNow i have just been told around 30KV / cm !!!! Thats 3 times the voltage I have been toldIt is common sense that air pressure, humididty, current, and time of day all affect air breakdown voltage, but:IS there any official way to determine exactly what air breakdown voltage is? ( such as KV/distance )
Official? In what sense? The great state of Louisiana (I think) was contemplating legislating the value of pi to be 3 for the simplification of children's schoolwork.
But seriously...There are tabulated values of breakdown voltage for spark gaps of various dimensions. The handbook of Chemistry and Physics used to have them, or, you can look for a sphere gap table or a rod gap table (google is your friend).
There has been a lot of published research on the breakdown fields for air and a number of gases at a variety of frequencies, from Paschen in the late 1800's on to the present. (e.g., right now, I'm involved in some work to quantify microwave breakdown in simulated Mars atmospheres)
If you want an equation: http://home.earthlink.net/~jimlux/hv/paschen.htm