The process of adjusting an instrument or device to a reference standard is referred to as:

• A. Calibration
• B. Angulation
• C. Scanning
• D. Correcting for distance amplitude variations

Answer: (A)

Calibration is the process of adjusting an ultrasonic instrument to a reference standard so its response matches known values. By using a reference block or other standard, you set the instrument’s gain, time base, and reference levels so that echoes from a known reflector appear at the expected amplitudes and positions. This ensures measurements are accurate and reproducible across sessions and equipment.

Angulation refers to changing the probe’s angle to change the beam path and locate features, not to aligning the instrument to a standard. Scanning means moving the probe over the surface to collect data, which is about data collection strategy rather than standardization. Correcting for distance amplitude variations is a post-acquisition or processing step to compensate for signal loss with increased path length, not the initial alignment to a standard.