I. INTRODUCTION Urban water supply is an important part of urban infrastructure and an indispensable leading industry in the construction of modern cities. In the wave of public utility marketization reform, with the attention and support of the government and the competent authorities of the Ministry of Construction, the city's water supply business has developed rapidly. Although the tap water business is developing rapidly, it is relatively backward in the metering of tap water. The original mechanical pointer meter has been used for nearly 100 years, and there are many unpredictable difficulties in meter reading. Therefore, there is a growing demand for improved water management, especially water meter performance.

Second, the status quo analysis and examples With the progress of the times and non-development of science and technology, in the water supply management, the drawbacks of ordinary water meters become more and more obvious. First of all, due to the fact that most of the water meter installations are currently indoors, when the meter reading is performed, it is difficult to ensure that the user can stay home at any time due to many factors such as work, study, etc., which may lead to overpayment and less due to the work of the meter reader. The phenomenon of income collection may cause users to have conflicts with the water supply management department. Second, due to the problems of meter reading cycle and the implementation of stepped water prices, many areas cannot calculate and collect water charges on time, causing confusion in management.

In the past 20 years, in order to improve this situation, some management departments have introduced various types of smart water meters, such as IC card water meters and CPU card water meters. However, in terms of application, it is a very embarrassing situation. The main factor that creates a passive situation is that product technology is not closed and performance is unstable. Mainly in the product quality, manufacturing standards, installation specifications, product prices, after-sales service, use management problems. On August 10, 2007, Beijing established a CPU card key system, which mainly involved system security, card issuance management, marketing counters, bank CPU card recharging, after-sales service, and infrastructure construction. However, due to CPU card prepaid meter anti-human attack interference problems, worry about replacing the battery, the problem of excessive prices, the overall application situation is not optimistic, many water meters back to the manual meter reading method. According to relevant sources, they revealed to reporters the amazing inside story of the IC card water meter transformation in Yinchuan City: The water company loan spent 200 million yuan to purchase 6 IC card water meters to carry out water meter conversions. The cost per installed household is equivalent to the residents' water fee for 10 years. However, after the renovation, the problem continued to replace more than 2000 pieces of IC card water meters each month, which caused a heavy burden on the company. The IC card water meter quietly retired from Yinchuan. Changshan County Water Supply Company in Zhejiang Province has installed and used IC card water meters in large numbers since 2001. After installation, fewer and fewer users have come to recharge, and complaints have become more and more. The reason is that many water meter valves cannot be automatically closed when they should be closed. If the water meter is turned off or the water meter is filled with water, the valve is automatically closed. The company spent more than three months to replace the water meter, which caused great economic, human and social impact. As of May 2007, the replacement rate of IC card water meters installed by the company reached more than 95%. These examples are sufficient to show that there are various hidden dangers in these prepaid smart water meters at the current location, which not only brings a lot of economic losses to residents, but also brings many management troubles to the water management department.