Air impedance

Are you thinking of the characteristic impedance here, or literally the number of ohms you see on a multimeter?

The characteristic impedance can be found with the permeability of free space and permitivity of free space and a physics textbook, should fall out about 377 ohms. I've assumed free space is going to be close enough to 'air' for you.

If you want the multimeter type then this is clearly dependant on the moisture content, temperature, ionisation, and distance. Air is a very poor conductor until it breaks down when it becomes an excellent conductor: lightning and arc welders for example, Sprow.

Hi,

I would like to make a device to measure the impedance of the air. I use a ac current source, (i.e.1kHz) to pass through two electrode in a fix distance. What is the possible value of the impedance of the air? Thank you very much!

Wayne

You don't want the impedance, you want the breakdown voltage, if I'm understanding what you're trying to do correctly. An air gap is an extremely non-linear sort of thing; a very high impedance UNTIL the electric field exceeds the breakdown level, and then a very low impedance. What exactly is it you're trying to do here?

Bob M.