Large-diameter water meters usually refer to water meters with a nominal diameter greater than DN50. They are mainly used for trade settlement measurement for industrial and commercial users, zonal measurement (DMA) of pipe network systems, and water measurement for fire protection, gardens, etc. Although the proportion of large-diameter water meters is small, the total amount of water measured is usually more than twice the total amount of household water meters, and even up to 4 times in industrially developed areas. Therefore, the measurement benefits of large-diameter water meters play a vital role in a region's water management and control of production and sales differences.

The selection of large-diameter water meters should follow the principle of feature matching, that is, the type characteristics of the water meter must match the water usage conditions and installation conditions, to avoid one-sided pursuit of the advancement of certain performance or functions while ignoring the matching of application scenarios. In most cases, the cause of metering inaccuracy is not caused by the unqualified metering performance of the water meter itself, but is often caused by the mismatch between the model and the application scenario. Once any characteristics of the water meter, not limited to measurement characteristics, do not match the application scenario, problems are a high probability event, and often manifest as comprehensive problems. Therefore, it only makes sense to choose a water meter with better measurement performance and richer application functions based on matching characteristics.

Matching and selection is a work that combines management and technology. It includes a cyclic process of planning, implementation, summary, and improvement. It requires a series of measures such as investigation and analysis, data statistics, similar comparisons, and experience inference.