Duane—
Your last pic, for a chloride level—is that reading the color of the liquid? I’m guessing that is a piece of professional equipment.
I looked for (inexpensive) electronic testers and got the impression they were really using just conductivity, then maybe gave readouts in other ways. I have a TDS meter (which I use constantly), and I suspect it does that.
Do you know of other types, that actually measure alkalinity or hardness?