2. The service life of the entire watch: The service life of the entire watch is a question worth discussing. Because the service life of the entire watch is theoretically determined by the device with the shortest service life. According to the national standard, this device is a water meter, but in fact, the service life of the water meter far exceeds the time limit stipulated by the national standard. Judging from the current actual manufacturing situation, it is reasonable to require the manufacturer's promised life span to reach 6 years.

3. Physical damage indicators: prepaid water meters must have a certain degree of physical damage, so it is necessary to adopt good integral shell protection measures. Of course, when using a prepaid water meter, its deck is a vulnerable part, which is an unsolvable problem. Therefore, it is necessary to fully consider the software protection process, so that the attack on the card socket is of little significance, even if the card socket is broken, it will not affect the normal operation of other parts of the prepaid water meter.


4. Anti-freezing performance indicators: The anti-freezing problem is mainly a matter of storage and use methods. The use of water meters does not need to be considered when the temperature is below zero, because the water has frozen and cannot be measured. However, during transportation and storage, temperatures far below zero may be encountered, which requires consideration. The value of this reasonable index should be in the range of -25 degrees to +50 degrees. The water meter within this range should not be damaged by freezing. When the temperature returns to normal temperature, the prepaid water meter should be able to work normally.