The PSØ81 is a system on chip for ultra low power and high resolution applications. It was designed especially for weight scales but fits also to any kind of force or torque measurements based on metal strain gauges. It takes full advantage of the digital measuring principle of PICOSTRAIN. Thus, it combines the performance of a 28-bit signal converter with a 24-bit microprocessor. Additional elements like an LCD driver, 3K ROM with many complex pre-defined functions, 2k EEPROM program memory and an integrated 10kHz oscillator round off the device. A small amount of external components is sufficient to build a complete weighing electronic.