Handheld ultrasonic flowmeter is a portable measuring instrument widely used for flow detection in various fluid pipelines. It uses ultrasonic technology to measure the flow velocity of the fluid and calculates the flow rate by the flow velocity and the cross-sectional area of ​​the pipeline. Compared with traditional mechanical flowmeters, handheld ultrasonic flowmeters have the advantages of non-contact, easy installation, and strong adaptability. They are particularly suitable for flow measurement in non-stop or complex pipeline systems.

Working principle

Handheld ultrasonic flowmeters mainly measure flow velocity based on the ultrasonic propagation time difference (TOF) principle or the Doppler effect principle. The specific method depends on the type used:

1. **Time of Flight (TOF)**
This method calculates the flow velocity based on the change in the propagation speed of ultrasonic waves in the fluid. When the ultrasonic pulse propagates along the flow direction of the fluid, the ultrasonic speed in the downstream direction will increase, while the ultrasonic speed in the upstream direction will slow down. By measuring the propagation time difference of the ultrasonic wave, the flow velocity of the fluid can be calculated.

Comparison between upstream and downstream**: The ultrasonic transmitter will install two sensors on the pipeline to transmit ultrasonic signals upstream (upstream) and downstream (downstream) respectively. By comparing the propagation time difference between the two, the flow rate can be calculated from the flow velocity and the cross-sectional area of ​​the pipe.

2. **Doppler Effect**
In a fluid, if there are bubbles or particles in the fluid, when the ultrasonic wave encounters these bubbles or particles, the frequency of the ultrasonic wave will change (i.e., the Doppler effect). The greater the flow velocity, the greater the frequency shift. By measuring the frequency change, the flow velocity can be calculated, and thus the flow rate can be obtained.

Flow Calculation

Once the flow velocity is obtained, the flow rate can be calculated by the following formula:

[
Q = v times A
]

Where:
- ( Q ) is the flow rate (m³/s or L/min, etc.).
- ( v ) is the flow velocity (m/s).
- ( A ) is the cross-sectional area of ​​the pipe (m²).

For different pipe shapes (such as round, square, etc.), the flow calculation formula may be different, but the core principle is based on the product of the flow velocity and the cross-sectional area of ​​the pipe.

Main features

1. **Non-contact measurement**:
An important advantage of handheld ultrasonic flowmeters is that they can be measured without direct contact with the fluid, avoiding contamination of the fluid or corrosion of the flowmeter.

2. **Convenience**:
The handheld design facilitates quick on-site measurement without complex installation. The device is compact and easy to carry, suitable for various on-site flow detection.

3. **High accuracy**:
Through high-frequency ultrasonic signals, handheld ultrasonic flowmeters can achieve high measurement accuracy and are suitable for a variety of flow monitoring needs.

4. **Wide range of application**:
Applicable to a variety of fluids, such as water, oil, gas, chemicals, etc., and can even be used in fluids containing bubbles or suspended particles (when using the Doppler effect).

5. **Non-destructive measurement**:
Ultrasonic flowmeters do not require cutting or changing the structure of the pipeline, so they are non-destructive measurement methods for pipelines.

6. **Real-time monitoring and data recording**:
Handheld ultrasonic flowmeters are generally equipped with real-time display and data storage functions, which are convenient for on-site recording and later analysis.

When the ultrasonic beam propagates in the liquid, the flow of the liquid will cause a slight change in the propagation time, and the change in the propagation time is proportional to the flow rate of the liquid. At zero flow, the time required for the two sensors to transmit and receive the sound waves is exactly the same (the only technology that can actually measure zero flow). When the liquid flows, the sound wave transmission time in the upstream direction is greater than the sound wave transmission time in the downstream direction. The relationship conforms to the following expression:

Description

The handheld ultrasonic flowmeter is suitable for online calibration and patrol measurement of liquid flow in various industrial sites. It has the characteristics of high measurement accuracy, good consistency, battery power supply, simple operation, and easy portability. It is small in size and light in weight. The product has been It has been exported to Japan, South Korea, Australia, the United States and other regions, and has been widely praised.

Measurement accuracy: better than 1%
Repeatability: better than 0.2%
Working power supply: 90~230VAC (built-in nickel metal hydride rechargeable battery, can continue to work for 12 hours after charging)
Installation method: external installation, simple and convenient operation
Display: 4 lines of Chinese characters display instantaneous flow, flow rate, cumulative flow, signal status, etc. on the same screen
Signal output: non-isolated RS232 (FUJI extended protocol) 1 isolated OCT output
Other functions: The built-in data logger can record time, accumulated flow, signal status, working time, etc. The standard data interface RS232 is used for network detection or exporting recorded data for self-diagnosis, prompting whether the current working status is normal.

specification

Product structure