Which sensors are used for weld seam inspection in the automotive industry?

Summary

Welding is critical in vehicle manufacture. Weld quality affects safety, body integrity, and durability. This report reviews weld inspection technologies and sensor applications used in the automotive industry, including thermal imaging, ultrasonic sensors, color sensors, X‑ray inspection, laser scanners, and magnetic particle inspection.

1. Thermal imaging: a non‑contact infrared instrument that maps surface temperature to evaluate weld integrity and detect defects.

2. Ultrasonic sensors: use sound waves to inspect internal weld defects (cracks, voids, inclusions) by measuring reflections and transit times.

3. Color sensors: not widely used for welding but can detect areas with color changes before/after welding to find missing welds in certain cases.

4. X‑ray inspection: a high‑sensitivity non‑destructive method to detect internal weld defects; requires strict safety and environmental controls.

5. Laser scanners: scan surface geometry to assess weld profile and surface finish with high precision in a non‑contact manner.

6. Magnetic particle inspection: uses magnetic particles to reveal surface and near‑surface defects in ferromagnetic materials.

In practice, combine techniques (e.g., thermal imaging + ultrasonic) to improve coverage and accuracy. Consider safety and environmental compliance when using certain methods. Image processing and CT scanning are additional complementary methods for comprehensive weld evaluation.

Weld inspection is essential to vehicle safety and quality; choose sensors based on inspection goals and combine methods to maximize reliability.