container in the printer by storing the compensation values after manufacture of the device any changes in the sensor characteristics that occur during or after manufacture of the device will be taken into account and corrected by the digital compensation system the positioning of memory 706 depends upon the particular printer configuration in a system where the inkjet printhead assembly and the ink supply are separately housed such as the system shown in fig1 a memory 706 is preferably positioned with each one of ink containers 110 116 e g positioned like memory 110 d shown in fig3 in a system where the inkjet printhead assembly and the ink supply are housed together in an inkjet cartridge memory 706 is positioned with the inkjet cartridge in use printer controller 80 addresses the integrated p ils system 700 digitally and reads the digital output from the p ils system 700 and the compensation values stored in memory 706 printer controller 80 compensates the digital output from a d converter 708 using the compensation values obtained from memory 706 thereby producing a corrected pressure value for each sampled uncompensated pressure value printer controller 80 then estimates the ink level in the associated one of ink containers 110 116 based on the corrected pressure values in one embodiment the calculated ink level is output from printer controller 80 back to memory 706 where it is stored thus even if the ink container with memory 706 is removed from the printer and put in a second printer the ink level in the ink container is easily obtainable by the second printer the digital compensation system.