Richard,

Frequency,particularly any thing to do with electricity is always referred to as Hertz, or a measurement number of complete cycles per second. PPM or pulses per minute is not correct. It really is the wrong choice of words,as it does not refer to the completed cycle between pulse and welding current and back again. Second it is not pulses per minute you are concerned with, it is number of completed pulse cycles per second. If You are simply referring to the number of Pulses per second, it is less accurate than referring to hertz. Practically does it make a difference? Lets take the setting of .5 hertz. If you have 1/2 of a pulse per second, that would mean that you are only measuring the actual Pulse part of the cycle. So it would take 2 seconds to complete the pulse stage of the cycle, or 4 seconds (if balance is set 50/50) to complete the entire cycle.

So with .5 hertz, the pulse cycle is actually completed in 2 seconds, and both low and high components of the pulse cycle have been accounted for.