BSGgeo

Additional load on the processor/batteries. Accuracy of the topo maps - specifically changed conditions - roads, cleared areas, developments, etc. Works in the air (airplanes, buildings, etc) where "ground" elevation would not be correct. I have had a 400 for about two weeks, and was at a road side VADOT sign this weekend where I was 9-10' off in elevation. Not bad, considering WAAS is what, +/- 10' horizontal - at best? Although I have not verified it, I am confident that the information used is based on position, not on the maps. ---------------------------- BSGgeo

I think the formula is right. But, you need to finish it. The top of the can is about 60 sq. inches, with a pressure difference of about 2.5 PSI. That gives you a force of 150 pounds, if you had to lift it straight up. Figure yeah, it would have been tough to open. Things you do when bored on a business trip.....It is too cold, dark and sleeting right now to go hunting. But tomorrow..... Allan