From: "Tesla list" <tesla@xxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: Re: Official air breakdown voltage?
Date: Fri, 25 Nov 2005 19:55:16 -0700
Original poster: "Antonio Carlos M. de Queiroz" <acmdq@xxxxxxxxxx>
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/inch
Now i have just been told around 30KV / cm !!!! Thats 3 times
the voltage I have been told
It 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 )
30 kV/cm at normal temperatures and pressures, but this the ELECTRIC
FIELD intensity that causes ionization in the air, and does not mean
that is 30 kV for each cm in a spark. The value is directly proportional
to the pressure of the air and inversely proportional to the absolute
temperature.
For two large parallel plates with rounded edges, the electric field
between them is very uniform, and there are really 30 kV for each cm
of spark.
For an insulated ball far from other objects, the figure means that
a ball with 1 cm of radius (and a well polished surface) requires
30 kV of potential (relative to distant objects) to ionize the
air around it.
Two balls with 1 cm of radius cannot hold a voltage of more than 60 kV
between them without corona or sparks, no matter what is the distance
between them (less if they are close).
Antonio Carlos M. de Queiroz