# RBDOF-F Fixed Doppler Ultrasonic Flow Meter

> Machine-readable summary of https://www.rbflowmeter.com/products/rbdof-f-fixed-doppler-ultrasonic-flow-meter — generated from the same product record the HTML page renders.
> R&B Instrument Inc..

## Facts

- **Model:** RBDOF-F
- **Category:** Ultrasonic Flow Meter
- **Canonical page:** https://www.rbflowmeter.com/products/rbdof-f-fixed-doppler-ultrasonic-flow-meter
- **Language:** en
- **Last updated:** 2026-10-18
- **Brand:** R&B Instrument Inc.

## Overview

Fixed Doppler ultrasonic flow meter for open-channel and partially-filled pipe flow with dual-depth area-velocity technology.

## Description

### Product Overview

The RBDOF-F is a fixed-installation Doppler flow meter for open channels and partially-filled pipes carrying dirty liquids, slurries and stormwater. Dual-depth technology combines pressure and backup ultrasonic level measurement, and self-transmitting/receiving mode keeps working at very low water levels.

Automatic flow calculation supports circular, rectangular, trapezoidal and U-shaped channels, with RS485/Modbus and 4–20 mA outputs for remote monitoring.

## Specifications

| Parameter | Value |
| --- | --- |
| Type | Fixed Doppler area-velocity, open channel / partially filled pipe |
| Accuracy | Velocity ±1%~±3%; water depth ±3 cm |
| Level range | Pressure type 0.02–3 m or 0.02–10 m |
| Temperature | Operation -5°C ~ +60°C; storage -25°C ~ +80°C |
| Output signal | RS485 (Modbus RTU), 4–20 mA, RS232 (model dependent) |
| Power supply | 10–30 VDC (12 VDC / 24 VDC options) |
| Protection | IP68 (sensor); IP65 (transmitter) |

## Key specifications

- Accuracy: Velocity ±1%~±3%, level ±3 cm
- Pipe size: Open channel / partially filled pipe
- Output signal: RS485 Modbus RTU, 4-20mA, RS232 (model dependent)

## Features

- Dual-depth technology with pressure and backup ultrasonic level measurement.
- Self-transmitting/receiving mode enables measurement at very low water levels.
- Automatic flow calculation for circular, rectangular, trapezoidal and U-shaped channels.
- RS485/Modbus and 4–20 mA outputs for remote data transmission.
- IP68 sensor and rugged PU cable withstand sediment up to 20 g/L.
- Signal strength indication detects siltation, dry pipe or high loading.

## Trade information

- Minimum order quantity: 1pc
- Lead time: in 10 workdays
- HS code: 90261000

## Contact

For pricing, lead time and customization, contact R&B Instrument Inc. via the product page above.