Item Subject: cc:Mail Text Thank you all who responded. I had failed to mention that this printed wiring spark-gap has a slot in between the sharp points (electric field enhancers to facilitate breakdown) and yes, the solder mask is removed so that only bare copper shows. The creepage is fully compliant to table 6 so carbon tracking is not an issue (except for excessive high voltage transients). I also know that the exact voltage of spark gap operation is not fixed as many variables will control that. Now, having clarified that, is there an exemption to the clearance rules of table 3 if the spark gap could be treated as a pwb component?
Thanks in advance Hans P.S. The radioactive material in encased spark gaps is usually Ni63 and the gas used is usually SF6 although other materials and gases have been used.
