Symbol 6274 from IEC 60417 - Title/Meaning: Electrodynamic instrument, ironless Function/description: To indicate the ironless instrument which operates by the interaction of the magnetic field due to a current in a movable coil with the magnetic field due to a current in one or more fixed coils.
Additional information: 
See also the symbol IEC 60417-6275.
IEC 60051-1 provides technical details.
Own work using: iso.org/obp/graphics/grs/de196592-f479-4cde-87aa-aa4d83968692 200.png
Vectorization:  Mrmw