I know of Hart Scientific, Isotech, and Pond Engineering (anyone know if they are still in business?).
What brand names of Fixed Point Cells and Furnaces are there? I don't count NPL, as they just make the cells (and I'm sure very well).
I'm trying to satisfy a need to have multiple options for some work (details which I can't put here).
But if anyone knows of other brand names (I'm figuring overseas), I'd appreciate it. I found some stuff by Yamari in Japan as well.
Don't forget INSCO.