induction compass

His magnetic and induction compass was awarded the "Brevet d' invention" by the Ministre de Industrie of the Kingdom of Belgium.

The use of air-filled induction compasses has declined over the years, as they may become inoperative or inaccurate in freezing temperatures or extremely humid environments due to condensation or water ingress.

The Earth inductor compass (or simply induction compass) is a compass that determines directions using the principle of electromagnetic induction, with the Earth's magnetic field acting as the induction field for an electric generator.