This is so wholesome, especially in contrast. I love it!

That is an excellent point. Yeah, PSI would totally read as pounds times square inches which would be something else entirely. Adding in the extra P would fix it, too. PPSI. Suppose it’s another thing that people just have to get used to, haha.

Because in^2 is generally said “square inches.”

So it’s “pounds per square inch.”

Sometimes “per” will get its own letter, like in PPM - parts per million - and sometimes it’s left off, as in PSI.