I have an arc between a tungsten electrode and a work piece. The length of the arc remains the same. If I vary the current over a reasonable range (so as not to deform the tungsten nor to reduce the arc to instability) does the electrical resistance of the arc change?

The reason I ask is that I am attempting to quantify the heat input from a pulsed TIG arc as compared to a constant current arc.

TIA,

Ken

p.s. If the resistance does change a bonus point to anyone who can point me to a formula for quantifying the resistance