A plug gauge comprising: a housing defining an internal volume and a longitudinal axis (A H), said housing comprising a plurality of first openings (104, 106) into said internal volume and a plurality of second openings (108, 110) into said internal volume; a plurality of first contact elements (112, 114), wherein each first contact element of said plurality of first contact elements is at least partially received in a respective one of said plurality of first openings in said housing; a first plunger received in said internal volume of said housing and defining a first plunger axis (A P1) that is aligned with said longitudinal axis of said housing, said first plunger being movable relative to said housing along said first plunger axis, wherein said first plunger is biased into engagement with said plurality of first contact elements to urge said plurality of first contact elements radially outward through said plurality of first openings; a first sensor sensing movement of said first plunger relative to said housing; a plurality of second contact elements (142, 144), wherein each second contact element of said plurality of second contact elements is at least partially received in a respective one of said plurality of second openings in said housing; a second plunger received in said internal volume of said housing and defining a second plunger axis (A P2) that is aligned with said longitudinal axis of said housing, said second plunger being movable relative to said housing along said second plunger axis, wherein said second plunger is biased into engagement with said plurality of second contact elements to urge said plurality of second contact elements radially outward through said plurality of second openings; a second sensor sensing movement of said second plunger relative to said housing; a first biasing element positioned to bias said first plunger into engagement with said plurality of first contact elements (112, 114); a second biasing element positioned to bias said second plunger into engagement with said plurality of second contact elements (142, 144), wherein said first plunger and said second plunger face each other. a housing defining an internal volume and a longitudinal axis (A H), said housing comprising a plurality of first openings (104, 106) into said internal volume and a plurality of second openings (108, 110) into said internal volume; a plurality of first contact elements (112, 114), wherein each first contact element of said plurality of first contact elements is at least partially received in a respective one of said plurality of first openings in said housing; a first plunger received in said internal volume of said housing and defining a first plunger axis (A P1) that is aligned with said longitudinal axis of said housing, said first plunger being movable relative to said housing along said first plunger axis, wherein said first plunger is biased into engagement with said plurality of first contact elements to urge said plurality of first contact elements radially outward through said plurality of first openings; a first sensor sensing movement of said first plunger relative to said housing; a plurality of second contact elements (142, 144), wherein each second contact element of said plurality of second contact elements is at least partially received in a respective one of said plurality of second openings in said housing; a second plunger received in said internal volume of said housing and defining a second plunger axis (A P2) that is aligned with said longitudinal axis of said housing, said second plunger being movable relative to said housing along said second plunger axis, wherein said second plunger is biased into engagement with said plurality of second contact elements to urge said plurality of second contact elements radially outward through said plurality of second openings; a second sensor sensing movement of said second plunger relative to said housing; a first biasing element positioned to bias said first plunger into engagement with said plurality of first contact elements (112, 114); a second biasing element positioned to bias said second plunger into engagement with said plurality of second contact elements (142, 144), wherein said first plunger and said second plunger face each other.