document updated 15 years ago, on Dec 19, 2008

Kilovolts will fry most multimeters. So how do you measure the output of your project?

estimate based on length of the spark gap (however, there are a number of other factors that have to be calculated in, or controlled for)
add a simple voltage divider, but be sure to use high-voltage resistors
if you're just interested in what the coil is doing, you can wrap a small pick-up coil around the main coil, and measure the voltage output of that.