By calibration, we refer to the information needed to establish the true amplitudes of signals.
There are two distinct aspects of calibration. First is signal calibration, the process of establishing the relationship between the sample values in analog-to-digital converter units (adus) and the physical units of the signals (millivolts, millimeters of mercury, etc.). Second is display calibration, the process of determining standard scales for displaying various types of signals (e.g., 10 mm/mV, 1 mm/10 mmHg).