I just wanted to mention that as a materials scientist myself, I use ternary plots all the time. They’re absolutely critical to some aspects of work with ternary atomic systems. My current work is in CuInSe_2, a solar material. We characterize our grown thin films (physical vapor deposition) with a scanning electron microscope (SEM) that has energy dispersive spectroscopy (EDS) for characteristic x-rays (given off by the thin film compound). The atomic % calculated by the absorbed characteristic x-rays are then plotted on a ternary plot to show us how much of each atom is in the film (assuming we don’t have contaminants etc.). Then of course phase-lines are added to the plot sometimes to show where critical regions of certain phases exist.

As a graduate student I usually ask any incoming undergraduate laboratory help to first plot ternary plots of the compounds we grow from our data. It’s always interesting to see how they come up with solutions to the problem of what is a somewhat non-standard plot for the rest of the world.

Excellent blog and post!
-Allen

Thanks, Allen. This is a very nice example of the use of ternary plots in the modern world. I can imagine how odd it must seem to new students. I’d really like to see one of your plots if you don’t mind emailing me an example. — Ron

Know of any such thing. I made one, but why..?

thanks

rhh

Note: Richard and I have been emailing back and forth about this since he submitted this comment, and I have been unable to find an example of a nomogram for Heron’s equation. The best I can find are nomograms based on the A=(1/2)bh formula, which of course yields a simple multiplication nomogram. Meanwhile, Richard has sent me his example of a nomogram in intercept chart form for this problem, and has graciously offered it for inclusion in a future blog post I am planning. — Ron