Symbol 6266 from IEC 60417 - Title/Meaning: Position of use, inclined Function/description: To indicate that the instrument to be used with the dial inclines (e.g. 60-degree) from the horizontal plane.
Additional information: 
See also symbol IEC 60417-6264 and IEC 60417-6265.
IEC 60051-1 provides technical details.
Own work using: iso.org/obp/graphics/grs/8e5553ea-1630-44bb-8086-d1a5a7b27b9f 200.png
Vectorization:  Mrmw