Research for Electronic Instrument Transforms Error Calibration Device

The excellences and important functions of electronic instrument are described firstly.The definition of amplitude error,phase error and composite error for digital output of EIT are given in the paper based on the standard of IEC60044-7 and IEC60044-8.Subsequently the design principle of error calibration device is introduced:it adopts the individual sampling circuit of Field Programmable Gate Array(FPGA),by the use of the project of the absolute error and all digital phase-locked loop according to the digital quantity of the standard corresponding to output signals.Software adopts C# to program and deal with the signals ground on non-synchronized sampling.The hardware is simple,the measurement is convenient and the datum is precise.