galvanoscope
/ɡælˈvænəˌskoʊp/
noun
- An instrument that shows whether an electric current is present, without measuring its strength.
- The teacher used a simple galvanoscope to demonstrate that the battery was working.
- A galvanoscope can tell you if a wire is carrying electricity, but not how much.
- They built a homemade galvanoscope using a compass and a coil of wire.