| A BTC probe (300) may comprise a housing (302) having a body (307), a neck (310) extending radially from the body (307) coupled to a hard lead (312) comprising a hard shield (502), a driven guard (506), and a lead wire (508), and a cap coupled at a top surface of the body (307) enclosing an interior volume of the housing (302). A sensor element (324; 424) may be disposed within the housing (302) and coupled to the lead wire (508). The sensor element (324; 424) may comprise a sensor head (326; 426) having a first vertex (602a; 602b; 602g; 604c; 604d; 604e). |
