Breakdown voltage of dry air compared to humid air, how much of difference?

AI Thread Summary
Humidity significantly affects the breakdown voltage of air at standard temperature and pressure (STP), as humid air contains more ions that facilitate current flow. The breakdown voltage of dry air is approximately 30kV per 2.54cm. In practical applications, such as with a Marx generator, the maximum voltage can reach up to 100kV in dry air conditions. The discussion emphasizes that the presence of moisture in the air decreases the breakdown voltage, making it easier for electrical discharges to occur. Understanding these differences is crucial for applications involving high voltage systems.
Agnostic
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How much will the humidity affect the breakdown voltage of air at STP.
 
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Agnostic said:
How much will the humidity affect the breakdown voltage of air at STP.
What makes you think it has any effect at all?

AM
 
Andrew Mason said:
What makes you think it has any effect at all?

AM


Common sense?

Humid air will have a much greater number of ions that can more easily facilitate a current through it.

Also, the breakdown voltage of dry air is 30kV/2.54cm.

I have a marx generator that has a maximum voltage of 55kV sparking over a distance corresponding to 100kV in dry air .
 
Agnostic said:
Common sense?

Humid air will have a much greater number of ions that can more easily facilitate a current through it.

Also, the breakdown voltage of dry air is 30kV/2.54cm.

I have a marx generator that has a maximum voltage of 55kV sparking over a distance corresponding to 100kV in dry air .
Starting here you might find some useful commentary on the subject

http://www.pupman.com/listarchives/2003/November/msg00428.html
 
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