Symbol 1976 from ISO 7000 - Title/Meaning: Grid density, normal 
Function/description: To indicate function on document reproducing equipment for obtaining normal grid density.
Own work using: iso.org/obp/graphics/grs/a6b44d8c-a70b-4d21-bae4-22f45cfe0193 200.png
Vectorization:  Mrmw