Metran-520 calibrator, together with reference pressure modules, is designed for accurate measurement and reproduction of absolute and gage pressure of liquids and gases, gas vacuum, DC voltage and current. It is used as a working standard for verification and calibration of various pressure measuring instruments, pressure transmitters with unified output electrical or digital signals in the HART protocol standard, measuring transmitters, secondary indicating and recording devices, reference pressure gauges, as well as for checking warning instruments of electric contact pressure gauges, pressure switches and power supply units.