A tank overflow protection system and method for measuring process temperature and pressure utilizing one or more piezoresistive pressure transmitters. The piezoresistive pressure transmitter includes a differential pressure sensor and a temperature sensor. Data from the piezoresistive pressure transmitters can be digitally communicated via a cable. The pressure transmitters convert signals indicative of temperature and pressure to a digital value and transmit the signals to a main processor printed wire assembly for final compensation, diagnostics, and transmission to a distributed control system. A differential pressure can be calculated by subtracting two digital pressure measurement values. The temperature measurement can be employed to calculate any changes in density for a user-defined reference value.