R400 Ultrasonic Smart Water Meter – Accuracy Technical Specifications

The ultrasonic smart water meter uses the time-of-flight ultrasonic metering principle. It calculates flow velocity and volume by measuring the time difference between ultrasonic signals traveling downstream and upstream. The R400 turndown ratio (Q3/Q1=400) is the key accuracy feature of this meter. It extends the minimum measurable flow, reduces the low-flow dead zone, and is ideal for residential fiscal metering and billing.

1. Core Metering Specifications

The R400 ultrasonic smart water meter covers three key sets of parameters:

Metering indicators: turndown ratio, accuracy class, starting flow, etc.

Operational parameters: maximum working pressure, pressure loss, temperature class, etc.

Deployment parameters: ingress protection rating, battery life, communication interfaces, etc.

These parameters directly determine low-flow measurement capability, long-term stability, and on-site adaptability.

Typical specifications: Turndown ratio R400, Accuracy Class 2, Maximum working pressure 1.6 MPa, Temperature class T30/T50/T90, IP68, battery life ≥6 years (typically 8 years, depending on communication frequency). For DN15, the starting flow can be as low as 0.003 m³/h.

2. Key Technical Features

Time-of-Flight Ultrasonic Metering Flow is calculated based on the time difference between downstream and upstream ultrasonic signals. This method offers high sensitivity to very low flow rates, which underpins the R400’s wide turndown performance.

Wear-Free Construction There are no moving parts, such as impellers or gears, inside the meter. There is no accuracy drift caused by mechanical wear, so metering performance remains stable throughout the battery’s service life.

Bi-directional Metering & Self-Diagnostics Separately measures and logs forward and reverse flow. It triggers alarms for sensor failure, empty pipe, reverse flow, low battery, and other faults, with active upload of abnormal status.

Low Pressure Loss & Multi-Angle Installation The straight-through ultrasonic measuring channel achieves a pressure loss class of Δp40 to Δp63, outperforming traditional mechanical water meters. Accuracy is maintained for horizontal, vertical, and inclined installations.

3. Typical Application

The R400 ultrasonic smart water meter primarily uses NB-IoT for communication. Optional interfaces include LoRaWAN, M-Bus, and RS485. It supports Modbus RTU and EN 13757, and can integrate with MQTT or custom industrial protocols based on project requirements. Historical flow data, alarm logs, and operating status can be stored, transmitted, and tracked.

Its IP68 rating and wear-free design make it suitable for outdoor meter pits, humid environments, and submerged conditions. It is well-suited for rural drinking water meter retrofits and long-term, maintenance-free applications.

4. Summary

The R400 ultrasonic smart water meter combines ultrasonic metering, a wear-free design, bidirectional diagnostics, and low pressure loss. The R400’s turndown ratio ensures reliable low-flow measurement. IP68 protection and long battery life enable deployment in harsh field conditions. Q3/Q1, starting flow, and dimensions for each nominal diameter are specified in the product datasheet and factory calibration certificate.

Compliance standards: GB/T 778—2018, JJG 162—2019, CJ/T 434