Symbol 3311 from ISO 7000 - Title/Meaning: Target rate per area Function/description: To identify the control that sets the target rate per unit of area. To indicate the target rate (quantity) per unit of area.
pay attention to orientation of symbolAdditional information: 
This symbol does not specify the material to which the target rate applies
Symbol may be simplified at small size reproduction by removing the inner circle.
Own work using: iso.org/obp/graphics/grs/a34f859b-d56b-41ac-8c8f-cb3d7201092a 200.png
Vectorization:  Mrmw