Showing a single dimensional value inside of a valid range is not unusual, whether using a bar or using a virtual gauge.
My problem is slightly different - I have a two-dimensional value. Temperature and pressure are interrelated - whether the temperature is ok depends on pressure, and vice versa.
Apart from displaying a numerical value, I need a graphical indication for the operator to be able to quickly tell if the current values are ok, are they near to an alarm value, or has it gone into an error territory (which of course will have it's own notification).
Below is a quick mock of the graphical part - two overlaid regions, with a dot to show the actual reading. Not shown in the mock are numerical readings. What I am unsure of is whether to add axes and whether to add crosshair-like lines from the dot to those.
Colors were just a quick pick for the mock, although I do intend to stick to a blue-red combo to be colorblind friendly. Probably should add outlines too.
- this is for industrial equipment, so the focus is on readability and being intuitive, not aesthetics
- there can be up to 24 such indicators on a single 24" screen