Hey Jim, hey all,
English, as everybody knows, is the language where every thing has ten different words denoting it, and in addition, every single word denotes at least ten different things. Therefore, in English, the meaning and use of words depends on the conventions established in a particular context or environment. For example, a “torsion box” does not really mean a torsion box, but an anti-torsion box 
Therefore, I am not sure if in English, the term → “probe” for the Triquetra 3-Axis Touch plate is completely semantically incorrect. But in the most meanings, “probe” describes something with which you penetrate something to explore something.
- (sciences) A small device, especially an electrode, used to explore, investigate or measure something by penetrating or being placed in it.
– Source: Probe – Wiktionary