The ESI PRT-73 Automated Precision Ratio Transformer meets or exceeds all of the requirements for a calibration standard in precision measurement applications. It is easily integrated into systems for either automated or manual calibration of ratio dividers, transformer standards, synchro/resolver standards, transformers, calibrators, and voltmeters. The PRT-73 is fully programmable via a standard IEEE-488 interface. Storing calibration procedures in the system controller increases the repeatability of measurements.