Function and feature 1. At present, SJJ-1X is the most powerful, most compact, lightest, portable, automatic multifunctional watthour meter calibration system with biggest current output domestically and the most desirable reference standard and lab test equipment. 2. With internal high-accuracy, wide-range and multifunctional standard reference, JJY-301 is capable of testing various watthour meter and electrical measuring instrument easily. 3. Large LCD display is used as the interface with high definition and Chinese language displayed. Using keyboard the operation is more convenient and simple. 4. High current output£¨0~100A£©, convenient for calibration of high current watthour meter. 5. Single phase power supply is convenient for users with various occasions. 6. It has multiple protection system with high speed, that makes the device more reliable. Also it has sound and light warning unit. 7. quipped with special keyboard, the device can indicate automatically the united unit and separated unit phase characteristics of all kinds of meters during user's manual verification, by which it is more convenient. 8. As required by the protocol, automatic test can be carried out on watthour meter's startup, creeping, fundamental error, standard deviation, 8-hour and 24-hour variation. 9. With the help of special intelligence software and rotary encoder, users can change arbitrarily each phase voltage, current,phase, frequency at any time and calibrate easily various digital or pointer type voltage, current, phase, frequency, etc. meters. 10. Having dedicated calibration software, JJY-301 can be connected easily to system computer to calibrate watthour meter and other AC digital/pointer type meter. Testing data can be processed and stored and exchanged by network. Diagram and table printing function is also possessed. 11. It can test watthour meters with different constant, and calibrate the constant. 12. The parameters, such as voltage, current, power(apparent, active, reactive), phase, power factor, frequency, etc. can be real-time measured. The real time vector diagram and harmonics analysis can be displayed also. 13. All types of bar code input is acceptable. 14. With RS485 port, it is very convenient to connect with all kinds of foreign and domestic watthour meters. 15. Automatic detection of communication protocol function is available 16. The communication protocol complies with all stipulations of DL/T645-1997 and IEC1107, and it can be modified as user's requirement. 17. Clock reference and GPS clock can be connected.