1.2.5-14 Target Area Definition

The target area, preferred combination of X- and Y-axis values, should be graphically defined.

Additional Information:
Monitoring a pressure-temperature display, which presents a saturation curve that bisects the subcooled water region and the superheated steam region, is an example of a task situation where graphic depiction of a target area should be provided. This sort of display is best used for detecting deviations from normal if a target area can be defined. By plotting a brief time history, one may be able to predict where the values are headed. Care should be taken to distinguish the current value from past values, especially when the values change slowly. This can be done by placing a symbol or code for the current value.