Norway Military Service in 1801

My 3 great grandfather, Peder Johannsen, is listed as a 'national soldat' in the 1801 census. http://digitalarkivet.arkivverket.no/ft/person/pf01058360000255 Being a soldier was not a career, as he is back on the Kalsem gård by 1804, married, and starting a family. Does anyone know of a source to find out where a 22 year old soldier might have served, or been doing at that time?