A Galvanometer is a device used to measure small electric currents. The Galvanometer with an aluminum case is a specific type of galvanometer that comes with a casing made of aluminum material to offer protection to the delicate components inside. The device consists of a coil suspended inside a magnetic field, which is mounted on a spindle.

The coil is attached to a thin pointer that rotates when a current passes through the coil. The device also has a mirror attached to the pointer, which helps in the precise reading of the deflection of the pointer. The aluminum case provides protection to the internal components and also acts as a shield against any external magnetic field interference.