Main Features: 1. Measuring energy of each phase separately, total energy is the summation of three phase's impulse with rare interphase interference; harmonics and variation of frequency and voltage hardly can do influence to the measuring accuracy of the meter, no calibration needed within long term operation; 2. Measuring positive and negative active energy (negative energy can be counted into positive energy). 3. Three phase power supply system, indication for failed phase, measuring accuracy may not be influenced even if one or two phases fail to work; 4. Provided with impulse test output, LED test output and remote impulse signal output; 5. Long-life and high reliability; 6. Excellent anti-tamper capability: by adopting anti-magnetism and anti-reverse counter combed with special circuit design.