How Do You Analyse a C-Scan Mapping?

C-scan mapping is the best ultrasonic testing method for the rapid inspection of large surfaces. Ultrasonic non-destructive testing techniques allow for the acoustic inspection of materials and the creation of complete inspection maps. The process is called C-scan mapping. Illustrated by a comprehensive palette, these volumetric integrity reports are as easy to interpret as conventional X-rays.

The basis of C-scan mapping

The ultrasonic flaw detector records the complete A-scan information and can be used to create a 2D C-scan map. Using the gates in the A-scan, each pixel of the C-scan map depicts the depth (time of flight) or amplitude of the echoes passing through that gate. Using a vibrant palette to represent % or mm values, the full volumetric integrity of the part can then be quickly analysed.

The linear array technique is particularly effective when performing high-resolution C-scan mapping and examining large surface areas. The technique can be used to evaluate composite parts or to assess the thickness or extent of corrosion on sheet metal/thin plates.

Amplitude or depth method?

As we will see below, depth and amplitude based C-scans may reveal complementary information and both mapping methods have their advantages which must be fully understood to properly support the work of the NDT professional.

Amplitude C-scans are often used to monitor the behaviour of specific parts of a part. Monitoring rear wall (BW) amplitudes can provide information about the presence of small pores in the mid wall (BW drop). On the other hand, monitoring a specific composite part can help to detect weak bonds (BW peaks) in the bonding process between two composite layers. 

Deep C-scans are often used to monitor the thickness of a part by providing information about the remaining wall thickness or by pinpointing abnormalities such as adhesions, large porosity or defects in the material.

Ultrasonic Flaw Detector

HS PA20-Ex Ultrasonic Flaw Detector is a phased array flaw detector with 32/128 detection channels, which can solve more complex phased array detection problems, Real-time analysis of inspection data, which is more suitable for ultrasonic inspection requirements of complex structures or materials, Such as electric fusion welding PE pipe, hot melt welding PE pipe; steel skeleton PE pipe electric fusion welding; composite material inspection, etc.

Advantages of ultrasonic phased array technology:

1. Real-time colour imaging, including A/B/C/D and S-scan, is convenient for defect interpretation, and will not misjudge or miss defect;

2. The phased array technology can realize linear scanning, sector scanning and dynamic depth focusing, so that it has the characteristics of wide beam and multi-focus at the same time, so the detection speed can be faster and more accurate;

3. The phased array has higher detection flexibility, and can realize functions that other conventional detection technologies cannot achieve, such as the detection of complex workpieces;

4. It is easy to detect defects in various directions and different positions, with a high defect detection rate, wide detection range, high quantitative and positioning accuracy;

5. The scanning device is simple, easy to operate and maintain; it is more convenient to use, no harm to the human body, no pollution to the environment;

6. The test results are less affected by human factors, and the data is easy to store, manage and call, and connect to a computer to print and view. You can also directly connect the mouse to operate on the instrument.

7. It can save a lot of costs. The multi-purpose of a probe + wedge at various angles can automatically generate graphic defect reports. If there is an internal network, you can directly send the quality inspection report to the data center for review.

The above information is provided by the ultrasonic flaw detector manufacturer.