Ohmic sensing with IPTM-60

With water on the table and too low short circuit current configured,
we get something like the orange curve. A damped curve with reduced "swing".
No sharp transitions between open and short circuit.
 

Of course I tried to fix this in software, therefor the four conditions to trigger a sensing contact
The right thing to do was to lower the R1 value and increase the short-circuit current.

 

Recorded the voltage between tip and work piece during some 5 minutes. Was cutting a bunch of small holes.
 

They all look like this one, with some variation.
 

This was on a dry work piece. There is a clear voltage drop, somewhat slow, delayed recovery.
Triggered contact condition was a one-cycle voltage drop of 5 Volts.