Tuomas Vohlonen

Tuomas "Tommo" Vohlonen (24 September 1877 – 27 March 1939) was a Finnish inventor. A surveyor by trade, his patents cover a wide area of devices and activities including compasses, skis, surveying, engines and farming. He founded the company Suunto Oy which is still active producing compasses according to his patented method as well as dive computers, sport watches and heart-rate monitors.

In April 1933, after experimentation with various designs, Vohlonen applied for a patent from the Finnish Patent and Registration Office for a compact liquid-filled field compass, in which the magnetic needle and damping fluid were completely sealed into a unitary fused celluloid capsule.^[1] Vohlonen was granted a patent on 25 January 1935.^[1] Together with his wife Elli and nephew Kauko he founded Suunto Oy in 1936. Vohlonen incorporated his new liquid-filled capsule into a lightweight wrist-mounted design, the Suunto M-311, suitable for use by soldiers, surveyors, hikers, and others navigating while afoot.^[1]