A pressure less than atmospheric pressure (a perfect vacuum is the absence of gaseous fluid).
The maximum change in output of a transducer when a specific amplitude and range of frequencies are applied to a specific axis at room temperature with no pressure applied.
The error recorded in output of a transducer when subjected to a given set of amplitudes and frequencies.
The resistance of a fluid to flow when subjected to shear stress.
is flow rate expressed as a fluid volume per unit time.