A measurement apparatus for determining a measure for the solid content of a liquid toner. The liquid toner includes a carrier liquid with marking particles, and the solid content is the ratio of the mass of the marking particles divided by the mass of the liquid toner. The measurement apparatus includes a measurement space for receiving liquid toner. The measurement space includes at least one hydrostatic pressure sensor configured and arranged for measuring data representative for the hydrostatic pressure caused by the liquid toner at least one predetermined position in the measurement space. The measurement apparatus also includes a controller configured for receiving the measured data and for determining a measure for the solid content of the liquid toner based on the received data.