The MI 3309 BT DeltaGT is both battery and mains powered multifunctional instrument intended to perform measurements for testing the electrical safety of portable electrical equipment. Integrated unique PRCD testing technology prevents tripping out of mains RCD during measurement. Due to dual power capability of MI 3309 it enables performing of differential leakage current test in spite of its lightweight portable design. Large graphical LCD with backlight, two PASS / FAIL LED indicators and HELP screens for each measurement make the handling of the instrument clear and simple. Up to 1500 test results with parameters can be stored in the internal memory of the instrument and then downloaded to the PC for further data handling and creation of test report. Lightweight design, pre-programmed and custom test sequences, optional barcoding, android keyboard application and RFID systems make the MI 3309 an ideal instrument for high volume professional safety testing of portable appliances.