What is "ammeters"

Usage examples of "ammeters".

An engine hung on chains from an I beam above garage disorder, tanks, tool cabinets, oilcans, ammeters, tires, tire lever and well, a folding chair behind a worktable of mallets, a board of car rings on hooks, vises and clamps and greasy rags everywhere, a beaded curtain marking off a personal area, and Arkady realized that he was directly below Pribluda's parlor.

Next he checked a bank of three ammeters, switching the monitor controls through each of the fuel cells to check their output.