Posted on 8/28/2026
Ultrasonic Water Meter Flow Ranges Explained: Q1, Q2, Q3, Q4, and R Ratio
Why Q1, Q2, Q3, Q4, and R matter
Water meter datasheets often list a nominal diameter, a permanent flow rate, an R ratio, and several flow points. These values are not interchangeable. They define the metrological operating range and help buyers compare meters that may have the same DN size but very different low-flow capability.
This article explains the flow-rate term...