 In the CGS system, the unit of the H-field is the oersted and the unit of the B‑field is the gauss.In the SI system, the unit ampere per meter (A/m), which is equivalent to newton/weber, is used for the H‑field and the unit of tesla is used for the B‑field.The unit was established by the IEC in 1930  in honour of the Danish physicist Hans Christian Ørsted.