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"Jozef" wrote in
: Hi Guys, Sorry if my post is not in the right group, I'm not a sailor or a boatsman. I purchased a pair of binoculars STEINER COMMANDER XP with (magnetcic) compass via internet. When I received de binoculars I remarked a big air bubble in the stabilising fluid and a deviation (with respect to a (magnetic) handcompass with optical prism) when shooting bearings. I sent the binoculars back to Steiner for repair and after three weeks my toy came back. The air bubble had disapeared but not the deviation. Due north with a reference compass the STEINER indicates 002.5° Due east with a reference compass the STEINER indicates 095.5° A quick series of measurements (beginning north and with increments of 30°) reveal a positive deviation with a maximum of +6.5° (from 0° to 180°) and maximum deviation of -5° (from 180° to 360°). Drawing a graph with de deviation values as a function of the bearing angle gives a sort of sinusoïdal curve. I contacted STEINER but got no reply yet. Are there STEINER users among you with similar experiences? Thank you for reading my post. Jozef http://www.astro.uu.nl/~strous/AA/en...he-velden.html This webpage says the magnetic declination for NL/BE is "less than 10 degrees". The pole is not at the physical rotation pole. The declination makes every point on earth read something different. The other variation is local variation. Magnetic outcroppings of iron ore may put compasses in the area where the outcropping is located off by many, many degrees. A compass never reads N at 000 degrees, unless you happen to be on that imaginary longitude where the declination is zero and the magnetic variation is zero. Anyplace else on the planet, a compass will be off by varying degrees, some as much as 10-15 degrees, either way, a combination of declination, the magnetic flux at the moment (which varies constantly), and the local magnetic variation caused by many things underground. Reading that compass in Belgium in open country isn't going to ever make it read N = 000 degrees. http://www.springerlink.com/content/r0r40358718524n5/ "BELGIUM 3. Kcenigsfeld L. Les Anomalies de la Variation Seculaire du Champ Magnetique Terrestre en Belgique de 1913 a 1957.- Institut Royal Meteoro- logique de Belgique, Publications Serie A, N13, 1963." You will find your exact declination and local anomalies at the World Data Center that collects it all: http://www.geomag.bgs.ac.uk/gifs/surveydata.html Fill in the forms to get it.......instead of buying it from the stupid booksellers across the planet that keep the data from public viewing if they can, so they can sell it to you. |
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