What is ultrasonic guided wave detection technology?

Ultrasonic guided wave detection technology uses mechanical stress wave to propagate along the extended structure, with long propagation distance and small attenuation. Ultrasonic guided wave detection technology is widely used to detect and scan a large number of engineering structures, especially metal pipelines around the world. Sometimes the detection of a single position can reach hundreds of meters. At the same time, ultrasonic guided wave detection technology is also used to detect the structure of rails, bars and metal plates.

In the guided wave test of pipeline, the low-frequency sensor array covers the whole circumference of the pipeline, and the generated axial uniform wave propagates along the front and back direction of the sensor array on the pipeline. Torsional wave mode is the most commonly used, but the use of longitudinal mode is limited. The device uses the pulses of the sensor array to set the excitation and detection signals.

Echo will be generated where the cross section of the pipeline changes or changes locally. Based on the arrival time of the echo, the distance between the origin of the echo and the position of the sensor array can be accurately calculated by the propagation speed of the guided wave at a specific frequency.

Guided wave detection uses distance amplitude curve to correct attenuation and amplitude drop to predict cross-sectional changes reflected from a certain distance. The distance amplitude curve is usually calibrated by a series of known reflected signal amplitudes (such as welds).

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Advantages of ultrasonic guided wave detection technology;

1. As long as the probe snap ring is installed in a certain section of pipeline (about 0.5m long), the pipeline with tens of meters on both sides of the snap ring can be quickly detected by 100%.

2. Air and underwater pipelines can be detected without working in the air or underwater.

3. The pipeline coated with thermal insulation materials can be detected, and the coating does not need to be destroyed except for the position where the probe is placed.

4. It can detect pipelines in difficult-to-enter parts, such as pipelines with pipe clamps, brackets and collars, pipelines blocked by walls, container walls and other pipelines or structural parts, pipelines under bridges and pipelines crossing roads and dams, without damaging structures that cause obstacles.

5. On-line detection can be carried out in the running state.

6. Check the site without electricity, no pollution, and do not affect the surrounding work. It can be operated by 2~3 people, and the inspection length is 5 kilometers per day (depending on the site situation).

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