Thc velocity low

This is the 9v battery test well it actually has 7.5v but according to the calculations it is ok? Those values 

Check the battery with a multimeter and then verify the arc voltage displayed in plasmac matches 

The voltage of the battery is 7.6v and this is mi plasmac values and configure.  

That would seem to be a problem then. 

These two values in the config tab are what control that:
It would seem that you have not calculated them correctly, as a 7.6v battery should show 7.6v on the GUI.

You might try this calculator to help you: jscalc.io/calc/NTr5QDX6WgMThBVb

Otherwise we'd need more info about your setup.

Another stab in the dark, but can you check what is the value of
plasmac.thc-feed-rate
pin?

Thanks guys for your time, these are the values, actually the scale was fine since when I took out the wires from the plasma voltage I forgot to put the 1M resistor.