Elma Combitest 425 is an innovative multifunction installation tester capable of carrying out safety tests on civil and industrial electric systems in compliance with IEC/EN61557-1. Furthermore the instrument is a 1 phase energy analyze and is capable of saving results of environmental parameters (illuminance, temperature), leakage current, active power, harmonics, power factor measurements on single phase systems, pre-installed autosequences, 6mA RCD test suitable for EVSE Electric Vehicle chargers,. The resistive TFT color touch-screen display, the icon menues, the on screen help and the userfriendly development make the instrument extremely intuitive even for unskilled users. Its numberless features grant the user a wide range of applications in the world of measurements. The multifunction installation tester Elma Combitest 425 allows saving all measures into an internal memory so transferring the saved data to a PC by means of USB (optional) or built in WiFi interface with an iOS or Android smartphones or tablet . The software supplied among standard accessories allows printing the testing reports. The instrument also drives optional short circuit adapter to carry out high resolution (0.1mOhm) loop/line impedance measurements with prospective short-circuit current calculation. This allows accurate measurements even close to power stations enabling the user to correctly size the protection devices in any system. Further possible tests consist in checking breakdown current, tripping current, I2t relative to breakers (MCB) with curves B, C, D, K and fuses type gG as well as aM and the percentage voltage drop on the main power lines. The test on earth leakage relay tester RCDs up to 10A (with optional accessory) is also possible with the instrument. Through optional clamp it is possible to measure the leakage current.