The positioning of the indicator card behind the pointer, the initial pointer shaft position, the linkage length and initial position, all provide means to calibrate the pointer to indicate the desired range of pressure for variations in the behavior of the Bourdon tube itself.
12.
The concepts of " total pressure " and " dynamic pressure " arise from Bernoulli's equation and are significant in the study of all fluid flows . ( These two pressures are not pressures in the usual sense-they cannot be measured using an aneroid, Bourdon tube or mercury column . ) To avoid potential ambiguity when referring to pressure in fluid dynamics, many authors use the term " static pressure " to distinguish it from " total pressure " and " dynamic pressure "; the term " static pressure " is identical to the term " pressure ", and can be identified for every point in a fluid flow field.