Which calibration practices are used for VT equipment?

• A. Verifying light intensity.
• B. All of the above.
• C. Ensuring magnification scales are accurate.
• D. Checking borescope focal length and camera resolution.

Answer: (B)

Calibration in VT ensures the imaging chain produces reliable measurements by checking multiple parts of the system. Verifying light intensity keeps illumination consistent so features aren’t missed or misinterpreted due to shadows or glare. Ensuring magnification scales are accurate guarantees that the size of detected defects is measured correctly, which is essential for sizing and acceptance decisions. Checking borescope focal length and camera resolution is important because proper focus and sufficient detail prevent distortion of geometry and loss of defect detail, affecting both detection and measurement accuracy. Since all of these aspects contribute to dependable VT measurements, the best choice is all of the above.