main function: single-phase electronic type ic card watt-hour meter can supply electric power only after being prepaid by users, one card for one user and one meter, and not interchangeable. when the electric power in the card is used up, the power will be cut off automatically, thus effectively avoid inconvenience of fee charging. meanwhile, the computer controls the power purchase information of users, which is convenient for checking, summing up, fee charging and bills printing, etc. the various technical parameters of single-phase electronic type prepayment watt-hour meters are in accordance with gb/t17215-1998 grade a and grade b static ac active watt-hour meter and the technical requirements for prepayment watt-hour meter. it adopts the most advanced ic card technology and smt technology in china, with complete function of double display, precise measurement, stability, safe and reliable, low power consumption and is easy to operate. technical parameter: 1. degree of accuracy: 1.0 2. specifications: 5(20)a, 5(30a), 10(40)a, 15(60)a 3. meter constant: 3200imp/kwh, 1600imp/kwh 4. reference voltage: 220v 5. reference frequency: 50hz 6. working voltage scope: 220v± 20% ac 7. power consumption: <0.5w 8. environment conditions for working: -20º c~+55º c, relative humidity not exceed 85% (+25º c) 9. data in the meter can be kept for 10 years on the condition of no power exists. ic card can be used for more than 100000 times. product feature: 1. mechanical wheel and led digital tube double display, the mechanical wheel can still display when there is a power failure or unexpected accidents, which can avoid disputes between the users and power management department. 2. it will alarm automatically when there is only 100 kwh electric power left, and power will be cut off when there is 20 kwh left, secondary alarming function is unique in china (the remaining electric power can be resumed after inserting card by the user, and continue to be used). 3. it adopts data automatically correcting technology; every piece of data is stored separately in 5 places. in case something is wrong with one datum, data in other four places can correct automatically, thus it is absolutely reliable and safe. 4. the components of ic card all adopt famous industrial parts, and key elements use original chips of us and japan, such as the measuring chips adopt ad7755, which ensure quality of the elements and the whole meter. 5. it adopts contactless ic card (rf card) patent technology which transmit wireless data outside the meter, thus with a function of waterproof, damp-proof and anti-attack.