The 15TDCL was built for the US, and worked fine up until July.

You know, I did see funny lights in the sky last July ... oh wait, that was Independence Day. Never mind.

Explanation: http://www.utm.utoronto.ca/~w3gibo/How%20to%20do%20field%20studies/properties_of_magnetic_field_at_.htm

Vector Explanation: http://www.ngdc.noaa.gov/seg/geomag/geomaginfo.shtml


Inclination Map: http://www.ngdc.noaa.gov/seg/geomag/icons/wmm2000i.gif

Compass Inclination Zone Map:
http://www.wide-screen.com/support/FAQsuunto.shtml#Anchor-60059

Brunton says that the 8099 is made for three regions: northern, equatorial, and southern.