I emailed the probe vendor as the tip is not concentric. He responded with some info on how it can be calibrated. I then searched and found this - http://www.machsupport.com/forum/ind...c,17766.0.html - Whilst this doesnt fix the actual issue, it looks like I can use the same prob or perhaps two of them for different uses (I bought two as I was importing it from the US anyways). Perhaps next time I should pay attention to the other stuff in the box.