Apparatus for measuring the filling level of a urea container having an ultrasound sensor and motor vehicle having a urea container

A urea storage device for a motor vehicle comprising:

• a urea container having a urea container bottom at a level and a sump lying below the level of said urea container bottom, said sump having an overall height and being downwardly bounded by a sump bottom and said sump adjoining said urea container bottom and having an open connection to said urea container;
• an apparatus for measuring a filling level of said urea container, said apparatus including:
• a sensor disposed in vicinity of said sump;
• said sensor having a sound-emitting surface configured to emit sound waves and to receive echoes of the same sound waves for measuring the filling level of said urea container by distance determination;
• and
• said sensor fitted on said urea container with said sound-emitting surface of said sensor adjoining at most the level of said urea container bottom, said sensor being disposed externally on said sump in a recess, and said recess protruding at least partially into said sump.