RBFM-AK Ultra_Low Flow Ultrasonic Flow Sensor

RBFM-AK Ultra_Low Flow Ultrasonic Flow Meter/Sensor Principle:

The RBFM - AK Series Clamp - on Flow Sensor operates based on advanced principles to accurately measure liquid flow within the specified small - diameter pipe range (DN6 - DN100 or 1/4 - 4").

1. Ultrasonic Principle

- The sensor uses ultrasonic waves to measure the flow rate. It typically employs the transit - time difference method. Ultrasonic transducers are mounted on the outside of the pipe in a clamp - on configuration. These transducers send and receive ultrasonic signals through the pipe wall and the liquid inside.

- When the liquid in the pipe is stationary, the transit time of the ultrasonic signal traveling upstream and downstream between the two transducers is the same. However, when the liquid is flowing, the transit time of the ultrasonic signal traveling downstream (in the direction of the flow) is shorter than that traveling upstream.

- The sensor calculates the time difference between the upstream and downstream transit times of the ultrasonic signals. Based on this time difference and the known speed of sound in the liquid (which is a characteristic of the liquid type), the sensor can determine the average velocity of the liquid flow.

2. Signal Processing and Calibration

- Once the time - difference data is obtained, the sensor's internal electronics process this information. The electronics use precise algorithms to convert the time - difference measurement into a flow rate value.

- Calibration is an essential part of the process. The sensor is calibrated to account for factors such as the pipe material, pipe diameter, and the properties of the liquid being measured. The calibration factors ensure that the calculated flow rate is accurate and reliable. Different liquid properties, like density and viscosity, can affect the speed of sound and the flow behavior. The sensor's calibration takes these variables into consideration to provide accurate readings across different liquid types.

3. Compatibility with Pipe Materials and Liquids

- The ability to work with various pipe materials (such as metal and resin) is due to the ultrasonic waves' ability to penetrate the pipe wall. The sensor is designed to work with different acoustic impedance characteristics of different pipe materials. The ultrasonic signals can effectively travel through the pipe wall and interact with the liquid inside without significant signal loss or distortion.

- For different liquids, the sensor's programming and calibration account for the differences in sound speed and other fluid - dynamic properties. For example, the speed of sound in water is different from that in oil or chemicals. The sensor adjusts its calculations accordingly to accurately measure the flow rate of each liquid type.

4. The Role of the Clamp - on Design in Operation

- The clamp - on design not only simplifies installation but also plays a role in the sensor's operation. By being attached to the outside of the pipe, it doesn't disrupt the internal flow of the liquid or cause any pressure loss. This is crucial for accurate flow measurement, especially in small - diameter pipes where even a small disruption could lead to significant errors.

- The design also ensures good contact between the transducers and the pipe surface. This contact is necessary for efficient transmission and reception of ultrasonic signals. The stability of the clamp - on attachment helps maintain consistent signal quality over time, enabling continuous and accurate flow rate monitoring.

In summary, the RBFM - AK Series Clamp - on Flow Sensor's working principle combines ultrasonic technology, signal processing, calibration, and an innovative design to provide accurate and reliable liquid flow measurement in small - diameter pipes.