ronixx 0 #1 June 3, 2014 Silly question. I recently bought a Viplo FT50. I set it to zero when i got it and placed it on my shelf at home. I have noticed after a couple days its moved forward to 500 feet. Is this normal?? The product control sheet that was filled out seems to fit within the allotted tolerances specified. ThanksUbique Quote Share this post Link to post Share on other sites
councilman24 36 #2 June 3, 2014 Altimeters, along with aad and any other skydiving accessory that measures 'altitude' actually measure air (barometric) pressure. As you go up the air pressure decreases. The air pressure also changes as the weather changes. This is why all devices need to be zeroed at the dz each day you jump. Some devices like aads automatically zero when you turn them on and continually rezero as the air pressure changes during.the day. Your mechanical altimeter will need to be rezeroed if the pressure changes during the day. They also DON'T always work. Check against another altimeter as you climb in the airplane. BTW do not check against the airplane altimeter. They are set to mean sea level and only read zero near the ocean. We care about height above the ground. If during.a.jump it seems to be moving slow or not changing use you first altimeter, your eyes. 'If in doubt whip it out.' In other words don't hit the ground wondering if your getting low. If everyone else is opening and your altimeter still reads 7000' take the hint. Altimeters sticking is.rare but.does happen. Many of us have 30 or 40 year old altimeters still working fine. I'm old for my age. Terry Urban D-8631 FAA DPRE Quote Share this post Link to post Share on other sites
jverley 1 #3 June 3, 2014 It's a barometric measuring device. Changes in atmospheric pressure will make it go up and down.John Arizona Hiking Trails Quote Share this post Link to post Share on other sites
wolfriverjoe 1,446 #4 June 3, 2014 Did the weather change? As in did a front go through? Significant pressure changes will make the altimeter reading change."There are NO situations which do not call for a French Maid outfit." Lucky McSwervy "~ya don't GET old by being weak & stupid!" - Airtwardo Quote Share this post Link to post Share on other sites
ronixx 0 #5 June 3, 2014 Yeah the weather today in Toronto was decently hot and a bit humid. Weather called for thunder and rain later today that never really happened. Thank you all for the detailed explanation ! Much appreciated !!Ubique Quote Share this post Link to post Share on other sites
