rea", where there is a specific maximum allowable error.Q3(Permanent Flow L/h): maximum flow under certain working conditions. At this flow rate, the meter should work properly and meet the maximum allowable error requirement.Q4(Max. Flow Rate L/h): The water meter is required to meet the maximum allowable error in a short period of time, and then to maintain the maximum flow rate of the metering characteristics under certain working conditions. STRUCTURESMART IC CARD WATER METERSmart IC card w