What is the terminology for infrared temperature sensors?

Hard magnetic materials: usually refers to magnetic materials with a coercivity of not less than 10KA/m.

Soft magnetic materials: usually refers to the magnetic materials with a coercivity of not less than 1000KA/m.

Magnetic flux meter: the use of the law of electromagnetic induction, the measurement of induced electromotive force on the principle of integration of time made by the measurement of magnetic flux changes in the direct-reading instrument.