the.com/galvanometer

means An instrument that detects and measures small electric currents by showing how much they deflect a magnetic needle or coil.

from Named after Luigi Galvani, the 18th-century Italian anatomist whose twitching frog legs — jolted by contact with two different metals — convinced the world that electricity could animate living tissue. His name became shorthand for electrical stimulation ('galvanize'), and when 19th-century scientists built devices to detect and measure current via a deflecting needle, they borrowed his name again, honoring the man who first made electricity visibly dance.