magnetic hardness comparator

magnetic hardness comparator

[mag′ned·ik ′härd·nəs kəm‚par·əd·ər]
(engineering)
A device for checking the hardness of steel parts by placing a unit of known proper hardness within an induction coil; the unit to be tested is then placed within a similar induction coil, and the behavior of the induction coils compared; if the standard and test units have the same magnetic properties, the hardness of the two units is considered to be the same.