Feature:1. Positive (0 degree) or negative (180 degrees) halfperiod phase angle can be selected to measure halfperiod.2. Tripping action current and action time AUTOAMP test can be measured at the same time.3. It is more convenient to keep the displayed measurement results for a certain period of time after the test is completed.4. It is used for safety measurement in electric power, manufacturing, smelting, chemical, household electricity and other industries.5. It is an ideal tool for the production, installation, inspection and maintenance of leakage protection switches.